A Cyclopædia of Practical Receipts, Processes, and Collateral Information (part 2)

1. Its colour and transparency is not affected by the addition of a little colourless oil of vitriol (Liebig), or by a solution of nitrate of silver, and subsequent exposure for some time to solar light (Vögel), unless either essential oil or organic matter be present, when it assumes a reddish tinge. 2. It should be neutral to test-papers, colourless, leave no residue on evaporation, and be miscible, in all proportions, with water and with ether. 3. Its boiling point should never be less than 170° Fahr.; a lower temperature suggests the presence of wood spirits, or acetone, or one of the ethers. To detect wood spirit (wood naphtha) see Nessler’s Test. For the reverse of this adulteration—the evasion of the duty by the introduction of spirit, under the disguise of naphtha, turpentine, &c.—see those articles.

4. The presence of water in alcohol may be detected, not only by the sp. gr., but also by white anhydrous sulphate of copper burning blue when dropped into it. 5. Potassium placed on alcohol does not take fire, unless a considerable per-centage of water be present.

Tests, &c. 1. It may generally be recognised by its volatility, inflammability, odour, taste, miscibility with water, power of dissolving camphor and resins, and other qualities already described. 2. If a few fibres of asbestos be ‘moistened’ with a saturated solution of bichromate of potash in oil of vitriol, and exposed to the smallest possible portion of hot alcohol vapour, it is almost instantly turned green, owing to the formation of oxide of chromium. In practice, the asbestos may be inserted in the neck of a retort, or even of a bulbed glass-tube containing a few drops of the suspected solution, when the effect occurs as soon as distillation commences. Ether and pyroxylic spirit produce a nearly similar result; but the ‘first’ of these is distinguished from alcohol by its not being miscible with water in all proportions; and the ‘other’ by Nessler’s Test; whilst both may be readily distinguished by their peculiar and characteristic odour. 3. Dissolve 3 pts. crystallised carbonate of soda in 10 pts. water. To this solution add 1 pt. of liquid to be tested, and heat to about 160° Fahr. Lastly, add iodine in small pieces, till it has entirely dissolved, and the liquid has become colourless. If alcohol be present, iodoform will make its appearance on cooling, and sink to the bottom in the form of a yellow powder. As a similar result is obtained with wood spirit, this must be proved to be absent before applying this test.

The only reliable method of proving that a sample is ethylic alcohol is the production of ether, by acting on the suspected liquid with sulphuric acid. See Ether.

Uses. In the arts, alcohol is used by the varnish-maker to dissolve resins; by the perfumer, to extract the odour of plants, and dissolve essential oils, soaps, and other similar substances; by the pharmaceutist, to prepare tinctures and other valuable medicinals; by the instrument-maker, to fill the bulbs of thermometers required to measure extreme degrees of cold; by the photographer, in the preparation of collodion; by the chemist, in analysis, and in the manufacture of numerous preparations; by the anatomist and naturalist, as an antiseptic; and by the physician, for various purposes and applications as a remedy. It is also frequently burnt in lamps, and in parts of the world where it is inexpensive, it is employed in the manufacture of vinegar. Its uses, when dilute, as in the ‘spirituous liquors’ of commerce, are well known. In medicine, it is employed both concentrated (‘alcohol,’ ‘rectified spirit’) and dilute (‘proof spirit,’ ‘brandy,’ ‘gin,’ &c.), as a caustic, irritant, stimulant, tonic, &c. It has also been used in a multitude of other cases, and has been applied to an almost infinite variety of other purposes.

Gen. commentary. The selection of any one of the processes given above for the preparation of alcohol must greatly depend on the convenience or position of the operator. Chloride of calcium, and quick-lime, from their powerful affinity for water, and easy application, are the hygrometric substances most generally employed; but the processes involving the use of the other substances and methods already noticed, have all of them advantages under particular circumstances. Gay-Lussac has recommended the use of caustic baryta instead of lime; and others have employed dry alumina, as an absorbent of the water prior to distillation. Common proof spirit may be concentrated until its sp. gr. falls to about 0·825, by simple distillation in a water bath; at which sp. gr. it contains only about 11% of water, by weight, and is then nearly as volatile as pure alcohol.

A convenient apparatus for the preparation of alcohol, on the small scale, is that figured in the engr., and which will be self-explanatory to every one competent to use it. The tank (i) should be supplied with ice-cold water; and the receiver (g) should be covered with cloths kept continually wet with water of the same temperature. The capsule or basin (c) is a water bath heated by the little gas furnace (d). On the large scale, for commercial alcohol, a copper still, fitted with a glass refrigeratory and receiver, is commonly employed.

By surrounding the capital of a still, or other like apparatus, by a water bath kept at the proper temperature, the alcoholic richness or content of the product may be regulated to the greatest nicety, for any desired strength.

The different statements of chemical authors as to the boiling point, specific gravity, &c., of alcohol, already noticed, may be referred to their having either experimented with samples which have not been absolutely anhydrous, or to their not having made the proper corrections for temperature, and for the different materials of which their vessels and instruments were composed—some probably having been made of glass, and others of brass or some other metal. In some instances the differences are more apparent than real, as in the Tables by Tralles and Lowitz; in the former of which water, at its lowest sp. gr., is taken as the standard. Until recently, the only known source of alcohol was the fermentation of saccharine solutions. Its production by synthesis, though often attempted, is, however, erroneously said to have always failed. It had long been employed as an occasional source of bicarburetted hydrogen (olefiant gas) at a high temperature; but M. Berthelot succeeded in reproducing it, from bicarburetted hydrogen, by agitating the latter, in a closed vessel, with sulphuric acid and metallic mercury (‘Journ. de Chimie Med.,’ 1855, p. 175); and Henry Flennel, nearly thirty years before M. Berthelot’s discovery, found that pure olefiant gas is absorbed by agitation with concentrated sulphuric acid, with the formation of sulphovinic acid, and that by subsequent dilution with water, and distillation, alcohol passes over into the receiver.

ALCOHOLATE. Syn. Alcohate; Alcoholas, L. A salt in which alcohol appears to replace the water of crystallisation, as is the case with certain chlorides, nitrates, &c. Some of them may be formed by simple solution and crystallisation of the salt in alcohol. (Graham.) They are all very unstable, being readily decomposed by water.

ALCOHOLIC. Syn. Alcoholicus, L.; Alcoholique, &c., Fr.; Alkoholisch, Ger. Pertaining to, containing, of the nature of, or made with, alcohol.

ALCOHOLICA. [L.] Syn. Alcoöliques, Fr.; Weingeist-verbindungen, Ger. In pharmacy, liquids containing, or preparations made with, alcohol, as a characteristic ingredient.

ALCOHOLISATION. [Eng., Fr.] Syn. Alcoholisatio, L.; Alcoölisation, &c., Fr.; Alkoholiserung, Ger. In chem. and pharm., the development of the characteristic properties of alcohol in a liquid, or the use of it either as an addition or a menstruum; also the act or process of obtaining alcohol from spirit by rectification.

ALCOHOLOM′ETER (-lŏm′-). Syn. Alcohol′meter (hŏl′-; -hŏm′-‡); Alcoholométrum, L.; Alcoölomètre, Alcoömètre, Alcoholmètre, &c., Fr. An instrument or apparatus used in alcoholometry. Alcoholometers are simply ‘hydrometers’ adapted to the densities of alcohol, either concentrated or dilute. Some of these, as Baumé’s, Carter’s, &c., merely indicate the number of degrees corresponding to the state of concentration of the liquid. Others, of a like construction, as those of Richter (a), Tralles (b), and Gay-Lussac (c), have their stems so graduated as at once to indicate the proportion per cent. of alcohol present, either by weight, or by volume, at some standard temperature. (See engr.) A third class, as those of the Abbé Brossard-Vidal, Field, &c. are essentially thermometers, with scales which indicate the boiling points of spirits of different strengths, instead of the common thermometric degrees; whilst to a fourth class belong the alcoholometer of M. Silbermann, which is based upon the known rate of expansion of alcoholic liquors by heat, expressed in alcoholometric degrees; and that of M. Geissler, which depends on the measurement of the tension of the vapour of the liquid, as indicated by the height to which it raises a small column of mercury. In Syke’s hydrometer, used by officers of the Revenue, the scale of the instrument is enormously extended by the use of movable weights, with each of which it becomes, in fact, a separate instrument, adapted to a certain range of specific gravities.

A very convenient alcoholometer for ordinary purposes (d) has been lately produced by some of the instrument makers. It is of the usual form, but its stem on one side exhibits the per-centage richness of the sample in alcohol by volume; and on the other, the per-centage by weight. Thus, both results may be obtained at one trial. This instrument is sometimes called Richter’s alcoholometer, in England. A further improvement, still more recently introduced, is a similar ‘double-scale’ instrument, showing the degrees of Sykes on one side, and carrying a small spirit-thermometer in the bulb, to which a scale is fixed ranging from 35° to 82° Fahr.

ALCOHOLOM′ETRY. Syn. Alcohol′metry (-hŏl′-; -hŏm′-‡); Spirit testing‡; Alcoholme′tria, L.; Alcoölométrie, Alcoömétrie, &c., Fr. In chemistry, the art or process of ascertaining the richness of spirits in alcohol. In commerce, the determination of the quantity of spirit of a certain strength, taken as a standard, present in any given sample of spirituous or fermented liquors. In England, this standard is called “proof spirit.”

Hist., &c. The great importance of being able accurately to determine the strength of spirits in the United Kingdom, on account of the high duties levied on them, has induced the Government authorities, at various times, to investigate the subject. In 1790, the matter was referred to Sir C. Blagden, then Secretary to the Royal Society, who instituted an extensive series of experiments to determine the real specific gravities of different mixtures of alcohol and water. The results of his labours and researches were put forward, with ‘Gilpin’s Tables,’ in 1794, but no practical measures appear to have been taken in consequence. In 1832 a committee of the Royal Society, at the request of the Lords of the Treasury, examined into the accuracy of the Tables, and the construction and application of the instrument (Syke’s hydrometer) now used by the Revenue officers, on which they reported favorably, and declared that they were sufficiently perfect for all practical and scientific purposes. The errors introduced into calculations of the strength of spirits by these tables were found to be quite unimportant in practice, and did not, in any one instance, amount to unity in the fourth place of decimals. This method adapts the specific gravity as the test of the strength of spirits, and is founded on the fact that alcohol is considerably lighter than water, and that (with proper corrections for condensation and temperature) the sp. gr. regularly increases, or decreases, according to the relative proportions in which the two are mixed.

Several other methods of alcoholometry have been proposed, founded upon—the variations in temperature of the vapour of alcohol of different strengths—the heat involved by its admixture with water—its dilatation by heat—the tension of its vapour—the insolubility of carbonate of potash in alcohol—its volatility, boiling point, &c. &c., the more important and useful of which are noticed further on. The method adopted by the Boards of Inland Revenue and Customs is, however, the one which is almost exclusively employed in trade and commerce in Great Britain, not only on account of its simplicity and correctness, but for the purpose of the results exactly coinciding with the results obtained by the Revenue officers.

METHODS OF ALCOHOLOMETRY.

1. Methods based on the specific gravity, or per-centage strength, by VOLUME:—

a. With Sykes’ Hydrometer. Revenue system. The engraving below represents Sykes’ hydrometer, as made by Mr Bate, under the directions of the Commissioners of Inland Revenue and Customs. It consists of a spherical ball or float, with an upper and lower stem, and is made of brass, which (in the more expensive instruments) is usually coated with gold, to prevent corrosion from damp, and the acidity so generally present in spirituous liquors. The upper stem (A) is about four inches long, and is divided into ten parts, each of which contains five subdivisions. There are nine movable weights of the form b, of different sizes, numbered respectively 10, 20, 30, &c., to 90, each of which represents so many of the principal divisions of the stem, as its number indicates. In use, one of these weights is slipped on to the lower stems; and thus, by means of them, the instrument acquires a range of above 500 divisions, or degrees, extending from the Revenue ‘standard alcohol’ (sp. gr. ·825) to water. It is so formed as to give the sp. gr. with almost perfect accuracy, at 62° Fahr. When loaded with the weight 60 it sinks in proof spirit to the line marked (P) on the narrow edge of the stem at 51° Fahr.; and, by further placing the square weight or cap (also supplied with the instr.) on the top of the upper stem, it floats exactly at the same point in distilled water. This weight or cap is found to weigh 43·66 grs., which is practically 1-12th of the total observed weight of the instrument, and its poise 60, and hence shows the difference between the gravity of proof spirit and water, as explained hereafter. The whole is fitted up in a neat mahogany case, accompanied with a thermometer, and a book of tables containing corrections for temperature, &c.—Process. A glass tube of the form of fig. B is filled to about the mark (a) with the sample for examination; the thermometer is then placed in the liquor, and stirred about for two or three minutes (observing not to breathe upon the glass, nor hold it in the hand), and the temperature noted. The hydrometer is next immersed in a similar manner, and gently pressed down in the liquor to the 0 on the stem with the finger; it having been previously loaded with any one of the nine weights that will cause it to float with the surface of the spirit at some point on the graduated part of the scale. The indication at the point cut by the surface of the liquor, as seen from below, added to the number of the weight with which the float is loaded, gives a number which must be sought in the hook of Tables, which is always sold with the instrument. In this book, at the page headed “Temperature as observed by the Thermometer,” and against the part of the column appropriated to the given indication (weight), will be found the strength per cent., expressed in degrees over or under proof, by VOLUME, in whole numbers or decimal parts. In reading off the indication, to ensure accuracy, it is necessary to allow for the convexity of the liquor at the part where it immediately rests against the stem.

Obs. In an instrument requiring so much care and skill in its manufacture the purchaser should be careful to procure a perfect one. A very slight blow, friction from continual wiping with a rough cloth, and other apparently trivial causes, tend to injure so delicate an instrument. The shape of the weights occasionally vary; some being intended to be attached to the hydrometer at the bottom of the spindle, and others to rest on its top. The first plan is, perhaps, the best, as it tends to make the instrument float with greater steadiness in the liquor; but, at the same time, it renders its adjustment by the maker a matter of greater difficulty.

In employing this instrument, the Revenue officers are instructed to take the nearest degree above the surface of the mercury, when it stands between any two degrees of the thermometer; and the division on the scale of the hydrometer next below the surface of the liquid, when it cuts the stem between any two lines; thus giving the difference in favour of the trader in both cases.

By means of the Table at page 64 the hydrometer indication, or the degrees over or under proof, of the Revenue system, may be converted into ‘real specific gravities,’ by mere inspection; and the corresponding ‘per-centage richness’ in alcohol of any sample may be found, either by WEIGHT or VOLUME.

The specific gravities in this table are such as, on being referred to Gilpin’s Tables, will give the expressions of proof strength answering to the whole indications of the Revenue hydrometer. Intermediate values at fifths of indications may be had by taking proportional differences between the nearest tabular numbers. Thus, to find the specific gravity that should stand opposite to Indication 70·6, we first obtain the difference between the densities standing in a line with Indications 70 and 71 respectively, and then say, as 1 : 0·6 :: ·00192. 00·115, and ·94135 + ·00115 = ·94250, the specific gravity required.

b. With GLASS ALCOHOLOMETERS. That of Tralles, and most others of a like description (as made in England), gave the per-centage strength, by VOLUME, with tolerable accuracy, at the standard temperature of 60° Fahr. Gay-Lussac’s ALCOÖMETRE, which closely resembles that of Tralles, is adjusted for the temperature of 59° Fahr. (15° Cent.). All of these, to give at once accurate results, must, of course, be employed at the ‘normal temperature’ of the instrument. As, however, in practice, the experiment cannot be conveniently performed at any ‘fixed’ temperature but only at that of the atmosphere, it is obvious that certain corrections are constantly required in order to obtain results of any value. Perfect accuracy requires that table for every variation of the thermometer, founded on actual experiments, should accompany each instrument; as, without them, tedious and difficult calculations are necessary, which, in the hurry of the cellar and laboratory, or by persons inexpert at figures, are not easily performed. A series of such Tables were prepared by Gay-Lussac, and, with his instrument, are those which are almost exclusively used in France. For rough purposes, in the absence of Tables or nicer calculations, it may be useful to know that, for commercial spirits, at ordinary temperatures, a variation of—

By Volume,

5° Fahr. is equal to (about) 1·00% of Alcohol; or (about) 1·794% of Proof spirit.

1° ” ” 0·20% ” 0·359% ”

5° Cent. ” 1·80% ” 3·229% ”

1° ” ” 0·36% ” 0·646% ”

By Weight,

5° Fahr. is equal to (about) 0·80% of Alcohol; or (about) 1·62% ”

1° ” ” ·16% ” ·32% ”

5° Cent. ” 1·43% ” 2·9% ”

1° ” ” ·28% ” ·58% ”

Table I.—Showing the Densities and Values of Spirits at 60° Fahr., corresponding to every Indication of Sykes’ Hydrometer.

Sykes’ Hydrometer Indication. Strength per cent. Specific Gravity. Per Cents. of Absolute Alcohol.

By Measure. By Weight.

O.P.

0 67·0 ·81520 95·28 92·78

1 66·1 ·81715 94·78 92·08

2 65·3 ·81889 94·31 91·42

3 64·5 ·82061 93·84 90·78

4 63·6 ·82251 93·33 90·07

5 62·7 ·82441 92·80 89·36

6 61·8 ·82622 92·29 88·67

7 60·9 ·82800 91·77 87·99

8 60·0 ·82978 91·25 87·30

9 59·1 ·83151 90·74 86·63

10 58·2 ·83323 90·23 85·96

11 57·3 ·83494 89·72 85·30

12 56·4 ·83661 89·21 84·65

13 55·5 ·83827 88·70 84·00

14 54·6 ·83993 88·17 83·33

15 53·7 ·84153 87·67 82·70

16 52·7 ·84331 87·10 81·99

17 51·7 ·84509 86·51 81·26

18 50·7 ·84680 85·95 80·58

19 49·7 ·84851 85·39 79·89

20 48·7 ·85022 84·81 79·19

21 47·6 ·85205 84·19 78·44

22 46·6 ·85372 83·61 77·74

23 45·6 ·85537 83·04 77·07

24 44·6 ·85700 82·47 76·39

25 43·5 ·85878 81·85 75·66

26 42·4 ·86055 81·21 74·92

27 41·3 ·86229 80·59 74·19

28 40·2 ·86402 79·97 73·47

29 39·1 ·86574 79·34 72·75

30 38·0 ·86745 78·71 72·03

31 36·9 ·86915 78·08 71·32

32 35·7 ·87099 77·40 70·54

33 34·5 ·87282 76·71 69·77

34 33·4 ·87450 76·08 69·06

35 32·2 ·87627 75·41 68·32

36 31·0 ·87809 74·72 67·55

37 29·8 ·87988 74·03 66·79

38 28·5 ·88179 73·29 65·98

39 27·3 ·88355 72·60 65·23

40 26·0 ·88544 71·86 64·43

41 24·8 ·88716 71·17 63·68

42 23·5 ·88901 70·43 62·89

43 22·2 ·89086 69·69 62·10

44 20·9 ·89268 68·95 61·32

45 19·6 ·89451 68·21 60·53

46 18·3 ·89629 67·47 59·76

47 16·9 ·89822 66·67 58·92

48 15·6 ·89997 65·93 58·15

49 14·2 ·90182 65·14 57·34

50 12·8 ·90367 64·34 56·52

51 11·4 ·90551 63·54 55·70

52 10·0 ·90732 62·74 54·89

53 8·6 ·90913 61·94 54·09

54 7·1 ·91107 61·09 53·23

55 5·6 ·91299 60·24 52·38

56 4·2 ·91479 59·43 51·57

57 2·7 ·91666 58·58 50·73

58 1·3 ·91839 57·78 49·94

U.P.

59 0·3 ·92037 56·86 49·04

60 1·9 ·92228 55·96 48·17

61 3·4 ·92408 55·10 47·33

62 5·0 ·92597 54·19 46·46

63 6·7 ·92798 53·22 45·53

64 8·3 ·92984 52·30 44·65

65 10·0 ·93176 51·36 43·76

66 11·7 ·93367 50·39 42·84

67 13·5 ·93586 49·34 41·86

68 15·3 ·93758 48·31 40·90

69 17·1 ·93949 47·29 39·96

70 18·9 ·94135 46·29 39·04

71 20·8 ·94327 45·20 38·04

72 22·7 ·94518 44·09 37·03

73 24·7 ·94709 42·96 36·01

74 26·7 ·94899 41·82 34·98

75 28·8 ·95092 40·63 33·92

76 31·0 ·95288 39·40 32·82

77 33·2 ·95484 38·10 31·68

78 35·6 ·95677 36·76 30·50

79 38·1 ·95877 35·32 29·24

80 40·6 ·96068 33·90 28·01

81 43·3 ·96259 32·41 26·73

82 46·1 ·96457 30·77 25·32

83 49·1 ·96651 29·08 23·88

84 52·2 ·96846 27·31 22·38

85 55·5 ·97049 25·39 20·77

86 59·0 ·97254 23·41 19·11

87 62·5 ·97458 21·39 17·42

88 66·0 ·97660 19·41 15·78

89 69·4 ·97857 17·46 14·16

90 72·8 ·98057 15·51 12·56

91 76·1 ·98261 13·58 10·97

92 79·2 ·98452 11·85 9·56

93 82·3 ·98657 10·04 8·08

94 85·2 ·98866 8·28 6·65

95 88·0 ·99047 6·83 5·48

96 90·7 ·99251 5·25 4·20

97 93·3 ·99448 3·80 3·03

98 95·9 ·99658 2·31 1·84

99 98·2 ·99851 ·997 ·793

100 ... 1·00000 ... ...

This Table {above} has been copied, by permission, from Loftus’s ‘Inland Revenue Officer’s Manual,’ and its correctness verified by W. H. Johnston, Esq., Surveying General Examiner.

Table II.—Table for finding the Specific Gravity of any Spirit at 60° Fahr., when the Specific Gravity at any other Temperature is given.

Water taken as 1000.

Specific gravity. Correction for
each degree. Specific gravity. Correction for
each degree.

810 to 820 ± ·475 910 to 920 ± ·434

820 ” 830 ± ·473 920 ” 930 ± ·424

830 ” 840 ± ·472 930 ” 940 ± ·406

840 ” 850 ± ·471 940 ” 950 ± ·381

850 ” 860 ± ·471 950 ” 960 ± ·340

860 ” 870 ± ·466 960 ” 970 ± ·269

870 ” 880 ± ·460 970 ” 980 ± ·165

880 ” 890 ± ·456 980 ” 990 ± ·090

890 ” 900 ± ·450 990 ” 1000 ± ·084

900 ” 910 ± ·442

Thus, by making the proper ADDITION to the apparent strength per cent., when the observed temperature is BELOW the normal temperature of the instrument, or a corresponding SUBTRACTION, when it is ABOVE it, the strength of the sample may be determined sufficiently near for all practical purposes.

The following Table, taken from Loftus’s ‘Inland Revenue Officer’s Manual,’ will be found of great value in making these corrections, and has the merit of being easily applied.

An example will show how this Table is to be used.

Example.—If a quantity of spirit is of the sp. gr. 894 at 73°, what will be its sp. gr. at 60°?

Here the sp. gr. being between 890 and 900, we must add ·450 for each degree of temperature between 73° and 60°. The sp. gr. at 60° would, therefore, be 894 + (·450 × 13) = 899·85. When the temperature is below 60°, the correction for each degree must be subtracted. When, however, very accurate results are desired, and the necessary Tables are not accessible, the sample for trial must be brought to the normal temperature of the instrument, in the manner explained under Hydrometry.

c. From the SPECIFIC GRAVITY. The temperature having been taken by a thermometer, and the specific gravity ascertained by any of the usual methods, but preferably by means of an accurate glass hydrometer, it merely becomes necessary to refer to Table I, where, against the number expressing the specific gravity, the alcoholic content per cent., by volume, of the sample examined, will be found for 60° Fahr., subject to the corrections just referred to, when the temperature is either above or below this point.

If the precise specific gravity sought cannot be found in the Table, the difference between it and the next greater specific gravity must be taken for the numerator of a fraction, having for its denominator the difference between the greater and the next less specific gravity in the table. This fraction, added to the per-centage of alcohol in the fourth column of the table, opposite the greater sp. gr., will give the true per-centage sought. Thus, the sp. gr. ·96051 is not in the table, and the next greater number is ·96068; the former must, therefore, be deducted from the latter, and the difference (17) put as the numerator of the fraction, having for its denominator 191, the difference between ·96068 and ·95877. The fraction (⁄191) ·089, so found, added to the per-centage strength opposite ·96068 in the third column, gives 33·989 as the true per-centage of alcohol in the given sample.

The per-centage by volume may be converted into per-centage by weight, by multiplying the former by ·793811, the sp. gr. of absolute alcohol, and dividing the product by the sp. gr. of the sample. The quotient is the number of pounds of alcohol in 100 pounds of the given spirit. Thus:—Suppose 1000 grains by measure of alcohol to weigh 950·92 grains, and to contain (see Table I) 40·63 per cent. by volume of absolute alcohol, what per cent. by weight does the sample contain?

·793811 × 40·63 = 32·25254093, and this product divided by ·95092 = 33·917, the true per-centage by weight of absolute alcohol in the sample.

2. Method based on the specific gravity, or per-centage strength by WEIGHT:—

The specific gravity is ascertained and the Table used in precisely the same manner as in the “method by volume,” already described.

The per-centage by weight may be converted into per-centage by volume, by multiplying the former by the sp. gr. of the sample, and dividing the product by the sp. gr. of absolute alcohol. This is merely the reverse of the operation described above.

Obs. The preceding methods of alcoholometry, as well as all others depending on the sp. gr. refer to UNSWEETENED SPIRITS only; and are inapplicable to those holding sugar in solution, or any other organic matter capable of altering the sp. gr. For sweetened spirits, fermented worts, wine, beer, &c., one or other of the following processes must be adopted:—

3. Other methods, adapted to either SWEETENED or UNSWEETENED SPIRITS, Tinctures, Fermented Liquors, &c.—

a. By DISTILLATION as originally proposed by M. Gay-Lussac. 300 parts of the liquor under examination (measured in a graduated glass tube) are placed in a retort or small still, and a quantity exactly equal to one third (i.e., 100 parts), carefully drawn over; a graduated glass tube being used as a receiver, and the operation stopped as soon as the distillate reaches the hundredth degree. The ‘alcoholic strength’ of the distilled liquor is then ascertained by any of the usual methods, and the result divided by three, when the per-centage of alcohol in the original liquor is at once obtained. If, from want of attention, more than 100 parts should be distilled over, the number which expresses the relation of the volume of the distilled product to the original bulk of the liquor tested, must be employed as the divisor. Thus, if 106 parts of liquor have distilled over (instead of 100), containing 33% of alcohol, the 300 must be divided by 106, which gives 2·83, and the 33% by this 2·83, which gives 11·66%, the true proportion of alcohol in the original liquor. The strength at ‘proof’ may be calculated from this in the usual way.

To ensure accurate results, the acidity (if any) of the liquor must be neutralised with carbonate of sodium, prior to distillation. It is also advisable to add 8% or 10% of common salt to the liquor in the retort or still; this, by raising the boiling point, causes the whole of the spirit to pass over into the receiver before the distillate has reached the required measure. This applies more particularly to weak liquors. With those of greater strength (as the stronger wines), it is better to distil over 150 parts, and divide the result by 2 instead of 3. To liquors stronger than 25% by volume of alcohol, or above 52% to 54% under proof, add about an equal volume of water to the liquor in the still, and draw over a quantity equal to that of the sample tested; when the alcoholic strength of the distillate gives, without calculation, the true strength sought. To liquors stronger than 48% to 50% (14 to 12 u. p.), add thrice their bulk of water, and do not stop the process until the volume of the distillate is double that of the sample tested, when the per-centage obtained must also be doubled. In each case a proportionate quantity of salt is employed.

Revenue Method. The following is the method adopted in the Inland Revenue and Customs Laboratories for the estimation of the per-centage of alcohol in wines, liqueurs, &c. A measure flask is filled up to a mark on its neck, with the wine, which is then carefully transferred to a distilling flask or retort, the traces of wine remaining in the former vessel being rinsed out with small quantities of distilled water, and the rinsings added to the wine in the latter vessel. About two thirds of the contents of the retort are then distilled over into the clean measure flask, and made up to the original bulk with distilled water, at the same temperature as the sample was previous to distillation. The strength is then taken by Sykes’ hydrometer, and this (if u. p.) deducted from 100, gives the per-centage of proof spirit in the wine. Thus:—

Strength of distillate = 74·6 u. p. = 25·4 per cent. proof spirit.

b. From the Temperature of the Vapour, as originally proposed by Gröning. The bulb of a thermometer is thrust through a cork into the head of the still, or other vessel employed, and the temperature of the vapour in which it is immersed being noted, is sought in the following table:—

Table III.—Showing the Alcoholic Content, by Volume, of Boiling Spirits, and of their Vapour, from the Temperature of the latter, as observed by a Thermometer. By Gröning.

Temperature of the Vapour. Fahr. Alcoholic content of the Distillate per cent. Alcoholic content of the Boiling Liquid per cent. Temperature of the Vapour. Fahr. Alcoholic content of the Distillate per cent. Alcoholic content of the Boiling Liquid per cent.

170·0 93 92 189·8 71 20

171·8 92 90 192·0 68 18

172·0 91 85 194·0 66 15

172·8 90⁄2 80 196·4 61 12

174·0 90 75 198·6 55 10

174·6 89 70 201·0 50 7

176·0 87 65 203·0 42 5

178·3 85 50 205·4 36 3

180·8 82 40 207·7 28 2

183·0 80 35 210·0 13 1

185·0 78 30 212·0 0 0

This method is admirably adapted to the purposes of the distiller and rectifier, as it furnishes a ready means of approximately determining the strength of the spirit passing over, at every part of the process of distillation, as well as that of the wash left in the still.

c. From the BOILING POINT, as originally proposed by M. l’Abbé Brossard-Vidal. This method is founded on the fact, that the boiling points of mixtures of alcohol and water, unlike water alone, are scarcely disturbed by the addition of saline, saccharine, or extractive matter within certain limits. It hence offers a ready means of determining the proportion of alcohol present in spirits, wines, fermented liquors, &c., with sufficient accuracy for all ordinary purposes. In applying it, a thermometer, with a large bulb and a narrow bore, and a movable scale graduated from 180° to 212° Fahr., is usually employed. Before using it as an alcoholometer, it is set, with its bulb immersed, in a small metallic boiler (brass or copper) containing distilled water, which is then raised to the boiling-point, and the 212° of the scale accurately adjusted on a level with the surface of the mercury, should it vary from that point. This is necessary on account of variations of atmospheric pressure causing corresponding variations of the boiling-points of liquids. It is then ready for several hours’ operations, and, generally, for an entire business day, without further adjustment. The little boiler is next filled with the liquor to be examined, and the lamp again lighted. The temperature as shown by the scale of the instrument at the commencement of full ebullition being ascertained, may be sought in one of the following Tables, against which the alcoholic content of the liquor will be found (nearly).

Table IV.—Exhibiting the BOILING POINTS of Mixtures of Alcohol and Water of the given strengths. By Gröning.

Boiling point. Fahr. Alcohol per cent.
by volume. Boiling point. Fahr. Alcohol per cent.
by volume.

205·34 5 179·96 55

199·22 10 179·42 60

195·8 15 178·7 65

192·38 20 177·62 70

189·50 25 176·54 75

187·16 30 175·46 80

185· 35 174·92 85

183·38 40 174·2 90

182·12 45 173·14 95

181·58 50 172· 100

Table V.—Showing the BOILING POINTS of ‘under proof’ spirit. By Dr Ure.

Boiling points.
Fahr. Per-centage
strength. Corresponding
Sp. Gr.

178·5 Proof. ·9200

179·75 10· U.P. ·9321

180·4 20· ” ·9420

182·1 30· ” ·9516

183·4 40· ” ·9600

185·6 50· ” ·9665

189· 60· ” ·9729

191·8 70· ” ·9786

196·4 80· ” ·9850

202· 90· ” ·9920

Obs. This method does not answer well with spiritous liquor above ‘proof,’ owing to the variations of their boiling point being so slight as not to be easily observed with accuracy; but with liquors under ‘proof,’ and particularly with wines, beer, and other fermented liquors, due care being observed, it gives results closely approximating to those obtained by distillation, and sufficiently accurate for all ordinary purposes. In testing strong alcoholic solutions it is, therefore, proper to dilute them with twice their bulk of water; and commercial spirits, with an equal bulk of water; the results obtained being doubled or tripled as the case may be.

d. From the EXPANSION of the LIQUID when heated: Silbermann’s DILATATOMETER. The expansion of alcohol between 0° and 212° Fahr. is triple that of water; and between 77° and 122° Fahr. it is much greater. Between -14° and -98° Fahr. the rate of expansion is about the ·00047th part in volume for every degree of Fahrenheit’s scale. The measurement of this expansion has been proposed as a new and ready method of alcoholometry, adapted to nearly all spirituous and fermented liquors. Silbermann’s instrument, which is based on it (see engr.), simply consists of a flat brass or ivory plate (A), on which are fixed a mercurial thermometer (D) graduated from 22° to 50° Cent. (= 77° to 122° Fahr.); and the DILATATOMETER (B), which is a glass pipette open at both ends. A valve of cork, or vulcanised india rubber, closes the tapering end (c); this valve is attached to a movable rod (C) which is fastened to the supporting-plate, and connected with a spring (f) and a handle (g) bearing a four-threaded screw, by which the lower orifice of the pipette can be opened or closed at will. In use, the pipette is filled with the liquor under examination, to a little above the zero point (0) on the scale. This is effected by suction, by means of a little piston of leather (i), which fits tightly in the long and wider limb of the pipette; the valve (d) being previously opened by turning the knob (h). The proper quantity of liquor being introduced, and the lower end closed, the piston is moved up and down two or three times, for the purpose of drawing the air-bubbles and absorbed air out of the liquid, the presence of which would vitiate the results of the trial. To allow the piston to be withdrawn without any shock, or the danger of dividing the column abruptly, the rod attached to it is made hollow throughout. In using it the operator applies the ball of his forefinger to the top of the piston-rod (E), in order to create a vacuum as he raises it; and then withdraws it, to readmit the air when he thrusts it down or removes it from the tube. The excess of liquid (if any) in the pipette is then run off until its upper surface is exactly level with the zero (0) of the scale, at 25° C., to which it is raised by immersion in a water bath of that temperature, as observed by the thermometer; which is done by very cautiously turning the rod which depresses the valve. The whole apparatus is now again immersed in the water bath; and, held by the upper portion of the plate, kept in gentle motion with the hand, until the temperature rises to exactly 50° C., when the coefficient of expansion is obtained, and hence also the proportion of alcohol—the scale of the instrument being so graduated, from actual experiments previously made upon mixtures of known composition, as to give, at once, the per-centage of alcohol by VOLUME (nearly).

e. From the TENSION of the VAPOUR:—Geissler’s ALCOHOLOMETER. This method, for which we are indebted to M. Geissler, of Bonn, depends on the measurement of the tension or elastic force of the vapour of the liquid, as indicated by the height to which it raises a small column of mercury. The spirit, wine, or other liquor, of which it is desired to ascertain the strength, is put into the little flask (a), which, when completely filled, is screwed on to the curved glass-tube which contains the mercurial column (which is inverted for the purpose), and is closed by the stop-cock (b). The instrument (see engr.) is then placed erect, and the flask and lower part of the tube immersed in a water bath, as in the previous method. The number, on the graduated scale of the instrument corresponding to the height of the mercury, at the boiling point of the liquor under examination, gives the per-centage of alcohol by VOLUME (nearly).

This method furnishes approximative results with great facility and expedition; and, with proper care, these do not vary more than ⁄3 to ⁄2 of 1%, from those obtained by distillation. We find, that by having the diameter of the part of the tube at which the surface of the mercury is acted on by the vapour a little larger than that of the longer limb, and by previously abstracting the air from the sample, as in Silbermann’s method, or even by agitation and exposure in an open vessel, the two may be made to correspond almost exactly.

f. From the DIFFERENCE between the sp. gr. BEFORE and AFTER ebullitiom:—Taberié’s method and ŒNOMETER. The sp. gr. of the sample is first accurately determined by any of the usual methods. It is next carefully evaporated, in an open vessel, to one half its volume. The residuum, when cold, is made up with pure water to exactly its original measure at its original temperature, and the sp. gr. again ascertained. The difference between the two being due to the spirit originally present, furnishes the means of calculating a new sp. gr., from which the per-centage richness of the sample may be obtained by mere inspection of the Tables. The observed sp. gr. is the true one, whenever the liquor, after ebullition and restoration to its original volume, has the same sp. gr. as water (i. e., 1·000), at 60° Fahr. Taberié employs a peculiar instrument, which he calls an œnometer; but its use is not essential to his method of alcoholometry. The results are, of course, only approximative, though sufficient for all ordinary purposes. Prof. Mulder, however, says that he prefers it to any of the previous methods; and that the results, with care, are almost as accurate as those obtained by distillation.

g. By means of CARBONATE OF POTASH:—

g. a. (Brande’s Method.) The liquor for trial is poured into a long, narrow glass tube (graduated centesimally), until the vessel is half-filled, and, after the solution of about 12% or 15% of a strong solution of subacetate of lead, or a little finely powdered litharge, is agitated until the colour is entirely, or nearly removed. Anhydrous carbonate of potash, in powder, is next added, until it sinks undissolved, even after prolonged agitation of the liquid. The whole is now allowed to repose for a short time, when the alcohol is seen floating on the top of the aqueous portion of the liquid in a well-marked stratum. Its quantity, read off by means of the graduations of the tube, and doubled, gives the per-centage richness of the sample in alcohol, by volume.

This process answers well with cordials, wines, and the stronger ales; but with very weak liquors it is not to be relied on. The whole operation may be performed in two to five minutes, and (with these exceptions) furnishes very reliable approximative results. In most cases the decolouring part of the process may be omitted. The alcohol thus separated has a sp. gr. of from ·8061 to ·8118, and contains 3% or 4% of water; but for ordinary purposes it may be regarded as pure alcohol.

4. Alcoholometry of MINUTE QUANTITIES of liquid. When only a few drops, or a quantity too small for the application of the preceding methods, can be obtained, an organic analysis may be had recourse to, and the quantity of absolute alcohol calculated from that of the resulting carbonic anhydride and water; care being previously taken to free the sample from other volatile bodies, if it contains any of them.

Gen. commentary. The duties on spirits in England are charged on the number of proof gallons they contain, which is ascertained by gauging or weighing the spirit, and then trying its strength by Sykes’ hydrometer. The per-centage of proof spirit multiplied by the number of gallons gives the net amount of proof spirit to be charged.

‘Proof strength’ is an arbitrary standard, adopted for the purpose of facilitating calculations, for which it is well suited; although pure alcohol would, for this purpose, be more simple. As defined by Act of Parliament, 58 Geo. III, c. 28, “proof spirit” is such “as shall, at the temperature of 51° of Fahrenheit’s thermometer, weigh exactly twelve thirteenth parts of an equal measure of distilled water.”

Taking, therefore, water at 51° Fahr. as unity, the sp. gr. of “proof spirit” at 51° Fahr. is ⁄13 of 1·000 or ·92308. When such spirit is raised to the temperature of 60° Fahr., its density is ·91984.

Spirit at “proof” contains very nearly equal weights of absolute alcohol and water; the exact proportions according to recent experiments are:—

By Weight. By Volume. Sp. gr. at 60° Fahr.

Bulk before admixture. Bulk after admixture and condensation.

Alcohol. Water. Alcohol. Water.

100·00 + 103·08 100·00 + 81·80 175·23 ·91984

49·24 + 50·76 57·06 + 46·68 100·00

The standard alcohol of the Revenue authorities, and that on which Gilpin’s Tables are founded, is a spirit of the sp. gr. ·825 at 60° Fahr., which is said to contain, by weight, 89% of pure alcohol of ·796; and 92·6% of alcohol, by volume, which corresponds to about 62·5 o. p.

It is of great importance to the spirit dealer to be able to estimate correctly the number of ‘proof gallons’ in any quantity of his commodities, or in the whole or any portion of his stock, as disagreeable errors frequently result from ignorance on this point. Calculations of this kind are extremely simple. Thus, when we find, by the hydrometer, that a given sample of spirit is 10 per cent. over-proof, it means, that 100 gallons of such spirit contain as much alcohol as 110 gallons of proof spirit.

In over-proof spirit, the per-centage o. p. always represents the quantity of water which the given spirit requires to reduce it to proof. By adding this per-centage over-proof to 100, we obtain a number which, multiplied by any number of gallons, and divided by 100, gives the exact number of proof gallons which is contained in any quantity of the spirit referred to. Thus:—A puncheon of rum gauged at 91 galls., and shown by the hydrometer to be 21 o. p., contains—

21 o. p. of sample added to 100 121

No. of gallons of rum 91

11011

No. of gal. of proof-spirit = 11011 / 100 = 110·11

In like manner when a spirit is said to be 11 u. p., or under-proof, it means that 100 gal. of such spirit contains 11 gal. of water, and 89 gal. of ‘proof spirit.’ By deducting the per-centage under-proof from 100, we not only obtain the number of proof gal. contained in 100 gal. of such spirit, but, as in the last case, a factor which multiplied by any number of gal., and divided by 100, gives the exact number of ‘proof gallons’ contained in any quantity of the given strength. Thus:—An ullage brandy piece containing 45 gal. of spirit at 10 u. p., would have the proof value of—

Per cent. u. p. of sample
10, subtracted from 100 90

No. of gall 45

4050

Quantity of proof spirit = 4050 / 100 = 40·50

Or exactly 40⁄2 gallons.

The strength of absolute alcohol (sp. gr. ·7938) is estimated at 75⁄4% over-proof. It therefore contains 175⁄4% of ‘proof spirit,’ whilst proof spirit (sp. gr. ·91984) contains 57·06% of ‘absolute alcohol,’ both being by measure or volume. Thus—

(meas. of alc. × 175⁄4) / 100 = equiv. meas. of pf. spt.

And—

(meas. of pf. spt. × 57·06) / 100 = equiv. meas. of abs. alc.

From which we derive the ‘constant multipliers’ 1·7525 (or roughly 1⁄4), and ·5706, applicable to any number of volumes or gallons. For—

meas. of alc. × 1·7525 = equiv. meas. of pf. spt.

and—

meas. of pt. spt. × ·5706 = equiv. meas. of alc.

To ascertain what quantity of a spirit at any given strength is equiv. to or contains 100 lbs. of absolute alcohol, we have only to divide the constant number 2207·7 by the proof value per cent. of such spirit. Thus—for a spirit 12 u. p.—this would be

100 - 12 = 88% of proof spirit;

and—

2207·7 / 88 = 25·1 gal. (nearly).

That is, 25⁄10 gal. of such spirit would contain 100 lbs. of absolute alcohol.

By removing the decimal point one place to the right, we have the equiv. measure of 1000 lbs. By removing it one, two, or three places to the left, we have it respectively for 10 lbs., 1 lb., and ⁄10 lb.; from which the equiv. for all other weights may be easily obtained.

By reversing the above operation, the measure of alcohol corresponding to any given weight of spirit, at any strength, may also be easily found.

The weight of 1 gal. of absolute alcohol being 7·938 lbs.; that of 1 gal. of proof spirit, 9·2 lbs,; and that of the ‘alcohol’ in 1 gal. of proof spirit, 4·53 lbs.; the weight of any number of gallons or volumes of either, and their equivalents, may be easily found. Thus:—

gallons of alc. × 7·938 = lbs. weight of alc.

gallons pf. sp. × 9·2 = lbs. w. of pf. spt.

and—

gallons of alc. × 16·121 = lbs. weight of pf. spt.

” pf. spt. × 4·53 = content in lbs. weight of alc.

In these cases a knowledge of the first four rules of decimal fractions is necessary, or, at least, advantageous; as the Excise officers carry their calculations to two figures of decimals, or ⁄100ths. Their plan is to reject the third decimal figure when less than 5; but to carry 1 to the next figure on the left hand, when it exceeds 5. Thus, 5·432 is set down as only 5·43; but 5·437 is written 5·44. In the delicate chemical processes of the laboratory, even greater accuracy is observed.

Formerly, spirit was said to be 1 to 3, 1 to 4, &c., over-proof, by which it was meant that 1 gal. of water added to 3 or 4 gals. of such spirit would reduce it to ‘proof.’ On the other hand, 1 in 5, or 1 in 8, under-proof, meant that the 5 or 8 gals., as the case might be, contained 1 gal. of water, and the remainder represented the quantity of ‘proof spirit.’ This method of calculation has now long given way to the ‘centigrade system,’ which not only admits of greater accuracy, but is quite as simple. It should be adopted by every spirit-dealer in England, from being that which is employed by the Revenue officers, whose ‘surveys’ it is absolutely necessary that the trader should understand, in order that his own estimation of his stock and his business calculations should correspond with theirs.

Several other methods of alcoholometry, besides those already noticed, have been adopted at various times, but the majority of them possess so little accuracy as to be quite inapplicable to the purposes of trade, and of the laboratory. Thus, the strength was at one time estimated by what was called the ‘proof.’ A little of the spirit was poured upon a small quantity of gunpowder, contained in a spoon or saucer, so as just to moisten it, and was then inflamed. If at the end of the combustion the gunpowder took fire, the spirit was held to be ‘above proof,’ if it only languidly fizzed away, or slowly burnt, the spirit was said to be ‘proof,’ but if the gunpowder failed to ignite, the spirit was esteemed ‘below proof.’ Hence arose the terms ‘proof’ and ‘proof spirit,’ which have since been adopted by Act of Parliament. Another method was that of dropping oil into the spirit; if the oil floated, the spirit was considered to be ‘under proof,’ if it sunk, it was rated as ‘proof’ or ‘over-proof.’ The ‘gunpowder test’ is quite fallacious; for, if a certain quantity of a spirit is capable of firing the gunpowder, a little excess of a spirit 20% or 25% stronger will often fail to do so, so much water being formed as to prevent the ignition. The ‘Preuve d’Holland’ test, of the French, or the ‘BEAD,’ is still frequently employed by persons unacquainted with the use of the hydrometer. It consists in shaking the spirit in a phial, and observing the size, number, and duration of the bubbles or beads, as they are called. The larger and more numerous these are, and the more rapidly they break and disappear, the stronger the spirit is presumed to be. This method is unreliable, as the presence of sugar or acid, even in minute quantities, will sometimes give to a weak sample the appearance of one many degrees stronger. Lovi’s beads are also often employed to ascertain approximately the strength of spirit, when a hydrometer is not at hand.

The insufficiency of most of the methods of alcoholometry here referred to, throws us back on the Revenue System (Sykes’ hydrometer), or on the specific gravity for unsweetened spirits. For sweetened spirits, as cordials, wines, beers, &c., there are none of the tests which give such accurate results as the distillation test, previously described as the Revenue Method.

The spirituous liquors of commerce being sold by measure, and not by weight, the methods of alcoholometry which give the results, per cent., by volume, are those we have chiefly explained. In the laboratory, the method by weight is that most generally employed in delicate processes and in analyses. By weight, the per-centage of alcohol remains the same for all temperatures, for the same sample; whilst by volume, the per-centage varies with the temperature of the liquid. This variation explains the cause of many of the sudden apparent decreases and increases, which occur in large stocks of spirits. Persons purchasing spirits during very warm weather, and paying for them according to their apparent quantity and strength, lose considerably by selling the same spirit when the weather becomes colder, without being conscious of such loss from the hydrometer. The reason of this is obvious, for, whilst the relative proportions of the alcohol to the water continue the same, the sp. gr. and the volume alter with the temperature; the latter being increased by warmth, and decreased by cold, in exact opposition to the former. Accuracy requires, in all cases, that a spirituous liquor should be tested for its strength at the temperature at which it was measured; and measured at the same temperature at which its strength was determined.

A consideration of these facts has led some of the great houses to introduce the system of weighing their spirits, instead of measuring them, the weight of an imperial gallon at 60° Fahr. being taken as the standard gallon. This is the method adopted by the Inland Revenue, at all distilleries, for assessing the duty, and will be readily understood by the following example:—

Cwts. qrs. lbs.

Gross weight of full cask = 13 2 27

Tare = 2 2 5

Net weight of spirit = 11 0 22

or 1254 lbs. Let us suppose the hydrometer indication to be 43·0, the weight per imperial gallon would be 8·903 lbs. (see Table VI), and 1254 ÷ 8·903 = 140 gallons.

Table VI.—Table for determining the Weight per Gallon of Spirits by Sykes’ Hydrometer.

A = Indication on Sykes’ Hydrometer.
B = Weight per Gallon.

A B A B A B A B A B
0 8·145 8 8·509 6 8·878 4 9·264 2 9·667
2 8·157 21 8·512 8 8·881 6 9·267 4 9·671
4 8·161 2 8·516 42 8·885 8 9·271 6 9·674
6 8·164 4 8·519 2 8·889 63 9·275 8 9·678
8 8·168 6 8·523 4 8·892 2 9·279 84 9·682
1 8·171 8 8·526 6 8·896 4 9·283 2 9·686
2 8·174 22 8·530 8 8·899 6 9·286 4 9·690
4 8·178 2 8·533 43 8·903 8 9·290 6 9·694
6 8·181 4 8·537 2 8·907 64 9·294 8 9·698
8 8·185 6 8·540 4 8·911 2 9·298 85 9·702
2 8·188 8 8·544 6 8·914 4 9·302 2 9·706
2 8·191 23 8·547 8 8·918 6 9·305 4 9·710
4 8·195 2 8·551 44 8·922 8 9·309 6 9·714
6 8·198 4 8·554 2 8·926 65 9·313 8 9·718
8 8·202 6 8·558 4 8·929 2 9·317 86 9·722
3 8·205 8 8·561 6 8·933 4 9·321 2 9·726
2 8·208 24 8·565 8 8·936 6 9·324 4 9·730
4 8·212 2 8·568 45 8·940 8 9·328 6 9·733
6 8·215 4 8·572 2 8·944 66 9·332 8 9·737
8 8·219 6 8·575 4 8·947 2 9·336 87 9·741
4 8·222 8 8·579 6 8·951 4 9·340 2 9·745
2 8·225 25 8·582 8 8·954 6 9·344 4 9·749
4 8·229 2 8·586 46 8·958 8 9·348 6 9·753
6 8·232 4 8·589 2 8·962 67 9·352 8 9·757
8 8·236 6 8·593 4 8·965 2 9·356 88 9·761
5 8·239 8 8·596 6 8·969 4 9·360 2 9·765
2 8·242 26 8·600 8 8·972 6 9·363 4 9·769
4 8·245 2 8·603 47 8·976 8 9·367 6 9·773
6 8·249 4 8·607 2 8·980 68 9·371 8 9·777
8 8·252 6 8·610 4 8·984 2 9·375 89 9·781
6 8·255 8 8·614 6 8·987 4 9·379 2 9·785
2 8·258 27 8·617 8 8·991 6 9·382 4 9·789
4 8·262 2 8·620 48 8·995 8 9·386 6 9·792
6 8·265 4 8·624 2 8·999 69 9·390 8 9·796
8 8·269 6 8·628 4 9·002 2 9·394 90 9·800
7 8·272 8 8·631 6 9·006 4 9·398 2 9·804
2 8·275 28 8·635 8 9·009 6 9·401 4 9·808
4 8·279 2 8·639 49 9·013 8 9·405 6 9·812
6 8·282 4 8·642 2 9·017 70 9·409 8 9·816
8 8·286 6 8·646 4 9·021 2 9·413 91 9·820
8 8·289 8 8·649 6 9·024 4 9·417 2 9·824
2 8·292 29 8·653 8 9·028 6 9·420 4 9·828
4 8·296 2 8·656 50 9·032 8 9·424 6 9·832
6 8·299 4 8·660 2 9·036 71 9·428 8 9·836
8 8·303 6 8·663 4 9·039 2 9·432 92 9·840
9 8·306 8 8·667 6 9·043 4 9·436 2 9·844
2 8·309 30 8·670 8 9·046 6 9·440 4 9·848
4 8·313 2 8·674 51 9·050 8 9·444 6 9·852
6 8·316 4 8·677 2 9·054 72 9·448 8 9·856
8 8·320 6 8·681 4 9·058 2 9·452 93 9·860
10 8·323 8 8·684 6 9·061 4 9·456 2 9·864
2 8·326 31 8·688 8 9·065 6 9·459 4 9·868
4 8·330 2 8·692 52 9·069 8 9·463 6 9·872
6 8·333 4 8·695 2 9·073 73 9·467 8 9·876
8 8·337 6 8·699 4 9·076 2 9·471 94 9·880
11 8·340 8 8·702 6 9·080 4 9·475 2 9·884
2 8·343 32 8·706 8 9·083 6 9·479 4 9·888
4 8·347 2 8·709 53 9·087 8 9·483 6 9·892
6 8·350 4 8·713 2 9·091 74 9·487 8 9·896
8 8·354 6 8·716 4 9·095 2 9·491 95 9·900
12 8·357 8 8·720 6 9·098 4 9·495 2 9·904
2 8·361 33 8·723 8 9·102 6 9·498 4 9·908
4 8·364 2 8·727 54 9·106 8 9·502 6 9·913
6 8·368 4 8·730 2 9·110 75 9·506 8 9·917
8 8·371 6 8·734 4 9·114 2 9·510 96 9·921
13 8·375 8 8·737 6 9·117 4 9·514 2 9·925
2 8·378 34 8·741 8 9·121 6 9·517 4 9·929
4 8·382 2 8·745 55 9·125 8 9·521 6 9·934
6 8·385 4 8·748 2 9·129 76 9·525 8 9·938
8 8·389 6 8·752 4 9·132 2 9·529 97 9·942
14 8·392 8 8·755 6 9·136 4 9·533 2 9·946
2 8·395 35 8·759 8 9·139 6 9·537 4 9·950
4 8·399 2 8·763 56 9·143 8 9·541 6 9·955
6 8·402 4 8·766 2 9·147 77 9·545 8 9·959
8 8·406 6 8·770 4 9·151 2 9·549 98 9·963
15 8·409 8 8·773 6 9·154 4 9·553 2 9·967
2 8·412 36 8·777 8 9·158 6 9·557 4 9·972
4 8·416 2 8·781 57 9·162 8 9·561 6 9·976
6 8·419 4 8·784 2 9·166 78 9·565 8 9·981
8 8·423 6 8·788 4 9·170 2 9·569 99 9·985
16 8·426 8 8·791 6 9·173 4 9·573 2 9·989
2 8·429 37 8·795 8 9·177 6 9·576 4 9·994
4 8·433 2 8·799 58 9·181 8 9·580 6 9·998
6 8·436 4 8·802 2 9·185 79 9·584 8 10·003
8 8·440 6 8·806 4 9·189 2 9·588 100 10·007
17 8·443 8 8·809 6 9·192 4 9·592
2 8·446 38 8·813 8 9·196 6 9·596
4 8·450 2 8·817 59 9·200 8 9·600
6 8·453 4 8·820 2 9·204 80 9·604
8 8·457 6 8·824 4 9·207 2 9·608
18 8·460 8 8·827 6 9·211 4 9·612
2 8·464 39 8·831 8 9·214 6 9·615
4 8·467 2 8·835 60 9·218 8 9·619
6 8·471 4 8·838 2 9·222 81 9·623
8 8·474 6 8·842 4 9·226 2 9·627
19 8·478 8 8·845 6 9·229 4 9·631
2 8·481 40 8·849 8 9·233 6 9·635
4 8·485 2 8·853 61 9·237 8 9·639
6 8·488 4 8·856 2 9·241 82 9·643
8 8·492 6 8·860 4 9·245 2 9·647
20 8·495 8 8·863 6 9·248 4 9·651
2 8·498 41 8·867 8 9·252 6 9·655
4 8·502 2 8·871 62 9·256 8 9·659
6 8·505 4 8·874 2 9·260 83 9·663

⁂ For further information in connection with Alchoholometry see Alcohol, Beer, Brewing, Distillation, Ebullioscope, Hydrometer, Hydrometry, Liqueurs, Malt-Liquors, Organic Substances, Saccharine, Specific Gravity, Spirit, Sugar, Syrups, Tinctures, Wine, Wort, &c. &c.

ALCOHOL; EFFECTS OF ALCOHOLISM. Without entering into the controversy as to whether the moderate consumption of alcohol, or its total disuse, is the more conducive to personal health and comfort—whether, as Dr Anstie and others have asserted it acts, when prudently taken, as a food—or whether, as other medical authorities contend, even its moderate use is a disturbing factor in the human economy—there need be no qualification of the assertion, that when the drinking of spirituous liquids of any kind is indulged in to excess, the habit, if persisted in, must sooner or later terminate in impaired health, serious disease, and premature death.

A powerful array of facts could be brought in support of this statement. For instance, in Nelson’s statistics we find it mentioned that—

A temperate person’s
chance of living is— An intemperate person’s
chance of living is—

At 20 = 44·2 years. At 20 = 15·6 years.

” 30 = 36·5 ” ” 30 = 13·8 ”

” 40 = 28·8 ” ” 40 = 11·6 ”

” 50 = 21·25 ” ” 50 = 10·8 ”

” 60 = 14·285 ” ” 60 = 8·9 ”

The average duration of life after the commencement of habits of intemperance is—

Among mechanics, working and labouring men 18 years.

” traders, dealers, and merchants 17 ”

” professional men and gentlemen 15 ”

” females 14 ”

Again, Dr Dickinson, writing “on the morbid effects of alcohol in persons who trade in liquor,” gave the results of an examination of 149 traders in liquor, as compared with 149 persons of various trades. The general results were diseases of the liver much more common in those who dealt in alcoholic drinks. In the lungs tubercle affected sixty-one persons of the alcoholic, forty-four of the non-alcoholic.

Tubercle in the brain, liver, kidneys, spleen, bowels, mesenteric glands, and peritoneum were twice as common in the alcoholic as in the non-alcoholic. The verdict, therefore, is unavoidable that alcohol (in excess) engenders tubercle in the brain, inflammations, atrophy, hæmorrhages; in the heart and vessels atheroma, hypertrophy, and other affections, were all more common in the alcoholic than in the non-alcoholic series. The evidence in kidney disease did not appear so conclusive, but some forms of kidney disease appear to be increased. The author sums up thus:—“Alcohol causes fatty infiltration and fibroid encroachment; it engenders tubercle, encourages suppuration, and retards healing; it produces untimely atheroma, invites hæmorrhage, and anticipates age. The most constant fatty change, replacement by oil of the material of epithelial cells and muscular fibres, though probably nearly universal, is most noticeable in the liver, the heart, and the kidney.”

Alcohol also seems to be the cause of special diseases, besides those more common and generally known ones, delirium tremens, alcoholism, &c. Of these we may mention one recorded by M. Galezowski, a peculiar affection of the eyes, which the doctor found very prevalent during the siege of Paris in 1870-1. In the five months of the siege fifty patients were affected by it, whilst during the twelve months preceding the siege only nineteen were to be found. Dr Galowski ascribed the malady to the habit of taking alcoholic drinks in the morning fasting. A peculiar kind of palsy has also been referred to alcoholic poisoning.

The following table, compiled by Dr Joseph Williams, lends support to the fact that an indulgence in alcohol is either the cause of insanity, or that it tends to its increase:

Total
admission. Proportion
caused by
intemperance.

Charenton 855 134

Bicêtre and Salpêtrière 2012 414

Bordeaux 156 20

Turin, 1830-31 158 17

Turin, 1831-36 390 76

Gard 209 4

United States 551 146

Palermo 189 9

Caen 60 16

Dundee 14 4

M. Parchappe 167 46

M. Batten 288 54

5019 940

Commenting on these figures, Mr Walter Blyth remarks, “There may be another explanation of the fact that many mad people have been great drinkers. A large proportion of those subject to insanity are driven by their morbid minds to drink; so that it may be that insanity causes drink, and not drink causes insanity.”

Many medical writers who are no advocates for the total abandonment of alcohol limit its consumption, in healthy people, to one or two fluid ounces a day, in the form of wine, beer, or spirits and water; two fluid ounces is, we believe, the quantity apportioned daily to every able-bodied seaman in the Royal Navy. Any slight habitual departure from this standard—even when the evidences of excess are not perceptible to others—all authority, historical, pathological, and physiological (unless it be given as a medicine), shows to be injurious. The researches of Anstie, Parkes, and Count Wollowicz, appear to prove that any quantity of alcohol exceeding an ounce and a half taken by an adult showed itself in the urine, a circumstance which these writers look upon as tending to show that the system has taken more alcohol than can be used in the body itself. In slight doses the action of alcohol is to produce a sedative effect upon the nerves, to redden slightly the lining membrane of the stomach, and to stimulate the secretion of the gastric juice.

Thus, in small doses alcohol may, and doubtless does, promote appetite. In excess, however, all these effects are turned to evil, and then ensue an inflammatory condition of the stomach, compression of the gland ducts from thickening of the tissue around them, excessive mucous secretion, and great loss of appetite. When carried into the circulation it greatly increases the force of the heart’s action, and at the same time paralyses, as it were, the restraining nervous supply to the arteries and small vessels, so that they can no longer oppose themselves to the blood-current, but dilate. This action in a small degree, occurring in persons of a weak and languid circulation, is no doubt beneficial; on the other hand, when in excess, it is most dangerous, and is a cause of the greater part of the diseases of the heart and great vessels.

“There appears to be a slight fall of temperature with moderate doses of alcohol, a very decided fall with excessive doses; the muscular and nervous systems are transitorily stimulated, and may do more work when small doses are given in cases of fatigue, but in other cases there is a marked torpor of the nervous and a want of co-ordination of the muscular system.”—Blyth.

Notwithstanding the researches of Percy, Strauch, Masing, Lallemand, Duroy, Parkes, Dupré, Anstie, Thudichum, and others, there is still a considerable divergence of opinion as to how alcohol is eliminated from the body. By some of the authorities just named it is affirmed to be eliminated as aldehyd, by others as carbonic acid; as to the latter, the experiments of Dr E. Smith show that the carbonic acid is decreased when brandy and gin are drunk, and increased by rum.

The only probable supposition, which facts support, tends to show that the alcohol is turned into acetic acid in the body, some of which unites with potash and other bases, and some is destroyed. All are pretty well agreed that in the form of spirits alcohol as a food is valueless, but that in the form of beer and wine it is possessed of a slight dietetic power, naturally varying with the amount and nature of the different substances held in solution in these beverages.

The imports of spirits into this country, in the seven years from 1850 to 1857, amounted to 70,740,980 gallons; whilst the imports in the seven years following, viz. from 1857 to 1864, were 78,016,071 gallons, showing an increase of 7,305,091 gallons. The population has, however, increased in the time, and a deduction on that account, as well as correction on one or two other heads, are required; still, that there is an increase is indisputable.

As respects France, a considerable increase in the consumption of spirits has taken place of late years, as the following table by M. Husson will illustrate:

The Mean Consumption of Spirits for each Inhabitant.

Litres. Litres.

From 1825 to 1830 8·96 yearly. ·024 daily.

” 1831 ” 1835 8·74 ” ·023 ”

” 1836 ” 1840 10·15 ” ·026 ”

” 1841 ” 1845 11·14 ” ·031 ”

” 1846 ” 1850 11·03 ” ·030 ”

” 1851 ” 1854 14·25 ” ·039 ”

In the United States, during the period from 1807 to 1828, the average was 27 litres for every inhabitant, which is even greater than the highest of the two sets of figures just quoted.

The demoralisation of the French army during the late Franco-Prussian war has been also unanimously ascribed to the excessive consumption of spirituous liquids.

The following results of an inquiry instituted in 1870 by the Massachusetts Board of Health into the comparative sobriety of different nations are gathered from an able paper which appeared in the ‘Medical Times and Gazette’ of April 15th, 1872, by Dr Druitt, in which he dissects and summarises the results in question. Dr Druitt writes:

“Highest in the scale of temperance come the Turks and Arabs; next the Iberians, Levantines, Greeks, and Latin races; lower down the Japanese, Scandinavians, Belgians, and the Irish Celt; lowest of all the so-called Anglo-Saxon of either continent.”

Professor Levi contributes to our knowledge on this subject by giving the following statistics:—In 1860 the committals for drunkenness in England and Wales were 88,000, and in 1870 134,000, an increase of 50 per cent.

In Manchester the increase from 1860 to 1870 was 375 per cent., or computed according to the increase of population 35·3 per cent. In London drunkenness is in the proportion of 5·43 per 1000, in Leeds 7·40, in Manchester 31·13, and in Liverpool 42·82. It must, however, be remembered that these figures are based on mere committals, which greatly depend on the activity of the police, and the noisy or quiet character of the drunkard.

We quote the following from Dr Blyth’s work on ‘Hygiene,’ without, however, attempting either to endorse or controvert what he says on the subject.

“Whether is Alcohol necessary or not. All experience, both at home and abroad, shows by facts that cannot be disputed that a person can do quite as hard work without alcohol as with it; and probably as the limits between moderation and excess are easily passed, and as the generality of mankind, even without intending it, err on the latter side, the result is that a comparison between total abstainers and even temperate men generally terminates in favour of the former. It would appear that total abstainers live longer, are better citizens, and can do more work than the rest of mankind. The figures of the “United Kingdom Temperance and General Provident Institution” go far to prove the above. This insurance society is divided into two sections. One section consists of abstainers, the other of persons selected as not known to be intemperate. The claims for five years anticipated in the temperance section were £100,446, but the actual claims were only £72,676. In the general section of the anticipated claims were £196,352; the actual claims no less than £330,297. In war the march of 2000 miles in his War of Independence by Cornwallis and his troops (1783), the Maroon war of Jamaica, the 400 miles’ march of an English army across the Desert from Komer, on the Red Sea, a march of 1000 miles in the Kaffir war, experiences at sieges, in action, in hot, temperate, and cold climates, where abstinence was either forced through circumstances or followed, shows to every unprejudiced mind that soldiers endure more fatigue, are healthier, and fight better, without stimulants than with them; and this fact is endorsed by every commander of the present day.

The excess and abuse of spirits, as before remarked, lost the French their military prestige in the Franco-German war. In very hot and very cold climates the Indian observers and the Arctic explorers all unite in condemning its (that is, the use of alcohol) use in the slightest excess, or even in moderate doses. It does not warm the body in cold climates, and the reaction that follows the exciting of the circulation is followed by a dangerous depression; whilst in hot it combines with the climate, and quickly produces disease.”

ALCOHOLIC DRINKS, EFFECTS OF. In addition to the serious injury to health caused by an excessive or imprudent indulgence in spirituous stimulants (see previous article), even a moderate and not injudicious use of them may often be attended with very disagreeable consequences—a more or less mild or modified form of poisoning, in fact—if the beverages themselves are, as very frequently happens, contaminated, either accidentally or intentionally, with certain objectionable ingredients. These ingredients are described under the articles Beer, Wines, and the various SPIRITS, such as Gin, Brandy, Absinthe, &c. Of spirit drinking it may be observed, that this dangerous practice is intensified by what is to be feared is the too prevalent custom of taking them undiluted, or “neat,” as it is termed. There is no doubt that they constitute the very worst form of alcoholic drinks, and shorten the lives of those who indulge in them to excess more summarily than any other intoxicating potion. The greatest and most ineradicable drunkards are almost always found to be spirit drinkers.

Liebig remarked that less bread was consumed in families where beer was drunk, and there seems to be little doubt that the different species of beer, including porter and ale, when pure and free from adulteration, act, although in a small degree, as food. Probably there are some who will agree with, whilst others will dissent from, Benjamin Franklin, who said “there was more sustenance in a penny loaf than in a gallon of beer.” The starchy extractive matters of the beer no doubt perform the same function in the animal economy that sugar does. It is well known that those who drink freely of beer mostly become corpulent, as witness the portly forms of draymen. The hop contained in the beer has doubtless tonic and stomachic qualities. We can speak with less certainty about the free acids contained in malt fluids. It is very certain that some people cannot drink a glass of beer without experiencing rheumatic pains in the joints, which effect is generally ascribed to the acidity of the beer; but which is really supposed to be due to the decreased elimination of urea and pulmonary carbonic acid from the system caused by the alcohol of the beer.

The heavy low-priced beers occasion drunkenness of a peculiarly violent and savage kind, a fact which strongly favours the inference that this form of intoxication is due to some toxic agent, used as an adulterant. Of wines, the clarets and subacid wines are undoubtedly antiscorbutic in properties, and light wines as beverages are preferable to the stronger. Port, sherry, beer, stout, and ale are almost universally condemned in cases where there is a tendency to gout. The light clarets and Rhine wines are far more desirable beverages when this is the case, and the German wines are said to be valuable drinks in many lithic affections. It seems probable that the ethers and the vegetable salts, together with the sugar contained in wines, perform the most important part in the human economy.

It has been proposed to introduce the red subacid wines as drinks for our sailors, because of their antiscorbutic qualities. Some of the alcoholic drinks prepared in India frequently cause temporary madness.

ALCOHOLISM. Alcohol; EFFECTS OF ALCOHOLISM.

AL′COHOLS. In chemistry, a term applied to compounds possessing a composition, formulæ, and chemical properties similar to those of ordinary alcohol. They form a series presenting an unmistakable symmetry, and differ from one another by well-marked gradations, as shown below:—

Methyl-alcohol (wood spirit). CH4O

Ethyl-alcohol (ordinary alcohol) C2H6O

Amyl-alcohol (füsel-oil) C5H12O

Capryl-alcohol C8H18O

Cetyl-alcohol C16H34O

&c., &c.

Alcohols. In commerce, pure spirits of a greater strength than about 58 o. p. (sp. gr. 8335), or containing more than about 85% by WEIGHT, or 90% by VOLUME, of pure alcohol, are commonly so called.

Alcohols. In perfumery, rectified spirit of wine, or commercial alcohol, holding essential oils or other odorous matters in solution.

Alcohols. In Fr. pharmacy, alcoholic tinctures and essences.

ALCOOLATIFS (alcoölatifs). [F.] Syn. ALCOHOLATI′VA, L. In Fr. pharmacy, alcoholic solutions of liniments, embrocations, &c., whether made by distillation, maceration, or solution.

ALCOOLATS (alcoölats). [Fr.] In Fr. pharmacy, spirits; applied by Béral, Henry and Guibourt, and others, to medicated distilled spirits.

ALCOOLATURES (alcoölatures). [Fr.] Syn. Alcoholatu′′ra, L. In. Fr. pharmacy, alcoholic tinctures, elixirs, &c. M. Béral confines the term to vegetable juices preserved by alcohol.

ALCOOLES (alcooölés). [Fr.] Tinctures; the ‘teintures alcoholiques’ of the Fr. Codex.

ALCOOLIQUES (alcoöliques). [Fr.] Syn. Alcohol′ica, L. In Fr. pharmacy, alcoholic or spirituous solutions. (Béral.)

AL′CORNINE (-nĭn). [Eng., Fr.] Syn. Alcor′nocine (-sĭn); Alcor′neum, Alcorni′na, L. A crystallisable substance, apparently intermediate between fat and wax, discovered by Biltz, in alcornoco bark.

ALCORNO′CO. Syn. A.-bark; Alcornoque, Fr.; Alkornoc, A.-rind, Ger. The bark of an unknown tree of South America. It is astringent and bitter, and has been highly extolled as a specific in phthisis; but appears to possess little medicinal virtue. The bark of the young branches of the cork tree (quercus suber), used in tanning, is also sometimes called alcornoco-bark; but possesses none of the characters of the former article.

AL′DECAY. The galls on the leaves of myrobalanus chebula (Gaertn.), a forest-tree of Bengal. Equal to the best oak-galls.

AL′DEHYD (-hīd). [al-(cohol)-dehyd (rogenatus).] C2H4O. Syn. Hydrated oxide of acetyle; Hydrate of othyle*; Hydroxide of O.* Literally, dehydrogenated alcohol. In chemistry, a peculiar ethereal liquid, first obtained in a pure form by Liebig, from alcohol. It is produced under various circumstances, particularly during the destructive distillation of certain organic matters, and in several processes of oxidation. The following are the most convenient methods of preparing it:—

Prep. 1. (Liebig.) Sulphuric acid, 3 parts; is diluted with water, 2 parts; and as soon as the mixture has cooled, alcohol of 80%, 2 parts, is added; and, subsequently, peroxide of manganese (in fine powder), 3 parts. The whole, after agitation, is then distilled at a very gentle heat, from a spacious retort into a receiver surrounded with ice, the connection between the two being perfectly air-tight. The process is continued until frothing commences, or the distillate becomes acid which generally occurs when about one third (3 parts) has passed over. The distillate is next agitated in a retort, with about its own weight of fused chloride of calcium, in powder; after which about one half only is drawn over at a very gentle heat (85° to 90° Fahr.), by means of a water bath. This rectification is repeated in a precisely similar way. The last distillate is ANHYDROUS ALDEHYD only slightly contaminated with foreign matters.

2. (Liebig.) Aldehyd-ammonia, 2 parts, is dissolved in an equal weight of distilled water; and, after being placed in a retort, sulphuric acid, 2 or 3 parts, previously diluted with rather more than its own weight of distilled water, and allowed to cool, is added. The whole is now distilled, by means of a water bath, into a receiver surrounded with ice, or (preferably) a freezing-mixture, the temperature of the bath at first being very low, and the operation being stopped as soon, or rather before the water begins to boil. The distillate is then placed in a retort connected with a well-cooled receiver, as before; and after all the joints are made perfectly tight, powdered fused chloride of calcium, in weight equal to that of the liquid in the retort, is added through the tubulature. The heat produced by the hydration of the chloride causes the distillation to commence, after which it is carried on, by means of a water bath, at a temperature ranging from 80° to 82° Fahr. This rectification being very carefully repeated, the last distillate is PURE ANHYDROUS ALDEHYD.

Prop., &c. Limpid, colourless, ethereal, neutral, inflammable; mixes in all proportions with alcohol, ether, and water; odour peculiar, penetrating, and, when strong, exceedingly suffocating, the vapour, in quantity, producing spasmodic contraction of the thorax; boils at 72° Fahr. (70°—Ure, 5th ed.); sp. gr. ·790 at 60°, and ·800 at 32° Fahr.; sp. gr. of vapour, 1·532; by exposure to air it is gradually converted into acetic acid, and speedily so under the influence of platinum-black; heated with caustic potash, a brown substance resembling resin (ALDEHYD-RESIN) is formed; gently heated with protoxide of silver, or its solutions, metallic silver is deposited on the inner surface of the vessel, in a uniform and brilliant film, whilst ALDEHYDATE OF SILVER remains in solution; heated with hydrocyanic acid it yields ALANINE. By age, even in close vessels, it passes into one or more isomeric compounds (ELALDEHYDE; METALDEHYDE), with change of properties. Aldehyde for experiments should, therefore, be always recently prepared; and it must be kept in a well-stopped bottle, in a very cold place, and preferably in ice.

Obs. Aldehyd is important for its assumed position in the acetyl-series, and the part which it plays in the process of acetification, &c. The word is now also commonly employed, by chemists, as a generic term for any organic substance which, by assimilating two atoms of hydrogen, yields, or would yield, a compound having the composition or properties of an alcohol; or which, by taking up one atom of oxygen, yields an acid. Many of the essential oils (as those of almonds, cinnamon, and cumin) are composed principally of bodies which may thus be called aldehyds. One of the most valuable properties of these substances, is their strong tendency to combine with the bisulphites of ammonium, potassium, and sodium; and by which they may be separated from complex mixtures.

AL′DEHYD-AMMO′NIA (-hĭd-). An ammonia-compound of aldehyd, discovered by Döbereiner and Liebig.

Prep. (Liebig.) Aldehyd (of process No. 1, above) is mixed with an equal volume of ether, in a flask surrounded with ice, or (what is better) a freezing-mixture; and is then saturated with dry gaseous ammonia. The crystals which soon form, after being washed with ether, and dried by means of bibulous paper and a short exposure to the air, are pure aldehyd ammonia.

Prop., &c. It smells like a mixture of turpentine and ammonia; melts at 165° to 170°; volatilises, unchanged, at 212° Fahr.; decomposed by exposure to the air; very soluble in water; soluble in alcohol, and more or less so in most other menstrua, except ether; acids decompose it. With sulphuretted hydrogen it forms thialdine.—Use. Chiefly to make pure aldehyd (which see).

AL′DER (awl′-). Syn. Al′der-tree; Al′nus (ăl-), L.; A. glutino′sa (Gaertn.); Betu′la alnus, Linn.; Aune, Aulne, Fr.; Erle, Ger. A well-known English tree, chiefly growing in moist grounds near rivers. Its wood is used for hurdles, for various articles of turnery and furniture, and when converted into charcoal, for making gunpowder; it possesses considerable durability under water; but is otherwise of little value. Bark and leaves very astringent, and reputed vulnerary; decoction used as a gargle in sore throat, and, in double the dose of cinchona, as a febrifuge in agues; bark and sap used in dyeing and tanning. The following belong to different nat. orders and genera to the preceding:—

Alder, Black. Syn. Win′ter-berry; Pri′nos verticilla′tus, Linn. A tree growing in the United States of America. Bark febrifuge, tonic, and astringent; berries tonic and emetic. (Bigelow.) It has been much recommended in dropsies, diarrhœa, intermittents, &c. Dose (of the dried bark), ⁄2 to 1 dr., 3 or 4 times a day.

Alder-tree, Black. Syn. Berry-bearing alder-tree; Rham′nus fran′gula, Linn. A large shrub found in the woods and thickets of England, &c. Wood, BLACK DOG′WOOD; bark, bitter, emetic, purgative; used to dye yellow; root-bark, a drastic purgative; berries, purgative, emetic; unripe berries yield SAP-GREEN; charcoal of the wood esteemed the best for gunpowder.

ALE. Syn. Barley Wine*; Aile, Fr.; Weiss-bier, Ger.; Ael, Eale, Sax.; Cerevis′ia alba, C. lupula′ta, A′la*, Al′la*, L. Pale-coloured beer, prepared from lightly dried malt, by the ordinary process of brewing. The ale of the modern brewer is manufactured in several varieties, which are determined by the wants of the consumer, and the particular market for which it is intended. Thus, the finer kinds of Burton, East India, Bavarian, and other like ales, having undergone a thorough fermentation, contain only a small quantity of undecomposed sugar and gum, varying from 1 to 5 per cent. Some of these are highly ‘hopped,’ or ‘bittered,’ the further to promote their preservation during transit and change of temperature. Mild or sweet ales, on the contrary, are less attenuated by lengthened fermentation, and abound in saccharine and gummy matter. They are, therefore, more nutritious, though less intoxicating, than those previously referred to.

In brewing the finer kinds of ale, pale malt and the best East Kent hops of the current season’s growth, are always employed; and when it is desired to produce a liquor possessing little colour, very great attention is paid to their selection. With the same object, the boiling is conducted with more than the usual precautions, and the fermentation is carried on at a somewhat lower temperature than that commonly allowed for other varieties of beer. For ordinary ale, intended for immediate use, the malt may be all pale; but, if the liquor be brewed for keeping, and in warm weather, when a slight colour is not objectionable, one fifth, or even one fourth of ‘amber malt’ may be advantageously employed. From 4⁄2 lbs. to 6 lbs. of hops is the quantity commonly used to the quarter of malt, for ‘ordinary ales,’ and 7 lbs. to 10 lbs. for ‘keeping ales.’ The proportions, however, must greatly depend on the intended quality and description of the brewing, and the period that will be allowed for its maturation.

The stronger varieties of ale usually contain from 6 to 8% of ‘absolute alcohol,’ ordinary strong ale, 4⁄2 to 6%; mild ale, 3 to 4%; and table ale, 1% to 1⁄2%; (each by volume); together with some undecomposed saccharine, gummy, and extractive matter, the bitter and narcotic principles of the hop, some acetic acid formed by the oxidation of the alcohol, and very small and variable quantities of mineral and saline matter. For the adulterants of ale, see Porter. See Beer, Brewing, Fermentation, Malt-liquors, &c.

Ale, Dev′onshire White. A liquor once generally drunk, and still in demand, in the neighbourhood of Kingsbridge and Modbury, Devon.

Prep. Ordinary ale-wort (preferably pale) sufficient to produce 1 barrel, is slowly boiled with about 3 handfuls of hops, and 12 to 14 lbs. of crushed groats, until the whole of the soluble matter of the latter is extracted. The resulting liquor, after being run through a coarse strainer, and become lukewarm, is fermented with 2 or 3 pints of yeast; and, as soon as the fermentation is at its height, is either closely bunged up for ‘draught,’ or is at once put into strong stoneware bottles, which are then well corked and wired.

Obs. White ale is said to be very feeding, though apt to prove laxative to those unaccustomed to its use. It is drunk in a state of effervescence or lively fermentation; the glass or cup containing it being kept in constant motion, when removed from the mouth, until the whole is consumed, in order that the thicker portion may not subside to the bottom.

Ales, Med′icated. Syn. Bryt′oles; Brutolés, Fr.; Cerevis′iæ Medica′tæ, L. In pharmacy, ale prepared by macerating medicinal substances in it, either at the ordinary temperature of the atmosphere, or when heated; infusions and decoctions, in which ale or beer is employed as the menstruum. The old dispensatories enumerate several medicated ales; such as CEREVISIA OXYDOR′CICA, for the eyes; C. ANTI-ARTHRIT′ICA, for the gout; C. CEPHAL′ICA, for the head; C. EPILEP′TICA, against epilepsy; &c. Preparations of this kind are now seldom ordered by the faculty, and their use is chiefly confined to the practice of empirics, and to domestic medicine. Bark, rue, savine, antiscorbutic plants, aromatic bitters, and stomachics, are the substances most commonly administered in this way. Ale in which wormwood, gentian, orange-peel, and the like, have been steeped, taken warm early in the morning, is much esteemed as a restorative tonic by drunkards and dyspeptics. See Beer, Purl, &c.

ALE′BERRY. A beverage made by boiling ale with spice, sugar, and bread-sops; the last commonly toasted. A domestic remedy for a cold.

ALE′GILL (g hard). Ale or beer flavoured or medicated by infusing the leaves of ground ivy in it; pectoral, stomachic, and nervine.

ALE′WIFE. The clupea serrata, an American species of herring. Its proper name is a′loof, although the established pronunciation and common orthography is ale-wife.

ALEM′BIC. Syn. Moors′head†; Alem′bicus, L.; Alambic, Fr.; Destillirkolben, Ger. An old form of distillatory vessel usually made of glass or earthenware, but sometimes of metal. The body (a) which holds the liquid for distillation is called the CU′CURBIT; the upper part (b) the HEAD or CAP′ITOL; (c) is the RECEIVER. It is still employed in the laboratory, in the distillation of articles that are apt to spurt over into the neck of the common retort, and thus vitiate the product.

ALEUROM′ETER. Syn. Aleuromètre, Fr. An instrument for determining the quantity and quality of gluten in wheat-flour, invented by M. Boland. It essentially consists of a hollow copper cylinder, about 6 inches long, and ⁄4 of an inch internal diameter. This tube has two principal parts; the one, about 2 inches long, is closed at the lower end, forming a kind of cup, into which the gluten is placed; it screws into the remainder of the cylinder. The cup being charged with a sample of gluten, and the upper part of the cylinder being screwed on, it is exposed in an oven, or (preferably) in an oil bath, to a temperature of 350 to 380° Fahr. From the length of the tube the gluten occupies in swelling, as measured by a graduated scale, its quality is determined. The ‘crude gluten’ of good wheat-flour augments to four or five times its original volume, when thus treated; but that from bad flour does not swell, becomes viscid and semi-fluid, and generally gives off a disagreeable odour; whilst that of good flour merely suggests the smell of hot and highly baked bread.

AL′GA. (-gă). [L.] Sea-weed. A common name of grass-wrack (‘zostera marina’—Linn.), though not one of the algæ.

AL′GÆ. (ăl′-jē). [L. pl.] Syn. Al′gals; Algæ (DC.), Al′gales (Lindl.), L.; Algues, Varech, Fr.; Alge, Meergrass, Seegrass, Ger. Sea-weeds. In botany, an order of Thallogens living in water or very moist places, nourished throughout their whole surface by the medium in which they live, having no distinct axis of vegetation, and propagated by zoöspores, coloured spores, or tetraspores. Linnæus defines them—“plants, the roots, leaves, and stems of which are all in one.” The algæ consist either of simple vesicles lying in mucus, or of articulated filaments, or of lobed fronds formed of uniform cellular tissue. Those that vegetate in salt water are popularly called SEA-WEEDS (fu′ci, L.) and LA′VER (ulvæ, L.); those found in fresh water CONFER′VÆ. One of their divisions (the Zoöspermeæ) comprehends the lowest known forms of vegetable life, being merely adhering cells, emitting, at maturity, seeds or sporules having a distinct animal motion. In Oscillatorias, the whole plant twists and writhes spontaneously; and Zymenas actually copulate like animals. Some of the Algæ possess great beauty. In the lower grades the colour is green; in the higher, red or purple.

Prop., Uses, &c. None of the Algæ are poisonous. Several are nutritious, emollient, and demulcent, from containing mucilage (carrageenin), starch, sugar (mannite), and a little albumen; and are hence used as esculents. The ash from the dried weed varies in different varieties from 9% to fully 25%; and contains variable quantities of potassa, soda, lime, magnesia, iron, manganese, and silica, with sulphuric acid, phosphoric acid, chlorine, and a little iodine and bromine. (Schweitzer; Forchhammer; Gödechens.) Sea-weeds, their charcoal, and their ashes, have been long regarded as alterative and resolvent; and anti-phthisic virtues have been attributed to them by Laennec and others. They were formerly much given in scrofulous affections and glandular enlargements; but their use is now almost superseded by that of iodine and its preparations. Dr Stenhouse has proposed some of the algæ as furnishing an economical source of mannite. The sea algæ are used for manure; their ashes form KELP.

The following table, showing the results of several analyses of different kinds of algæ, and illustrating the very large amount of nitrogen contained in them, is from Mr Walter Blyth’s excellent dictionary of ‘Hygiene and Public Health.’

Kinds of Algæ. Water. Dry matter. Per cent. Nitrogen
in dry matter. Protein contained
in dry matter.

Chondrus crispus, bleached, from Bewlay Evans. 17·92 82·08 1·534 9·587

Chondrus crispus, unbleached, Ballycastle. 21·47 78·53 2·142 13·387

Gigastina mamillosa, Ballycastle. 21·55 78·45 2·198 13·737

Chondrus crispus, bleached, second experiment. 19·79 80·21 1·485 9·281

Chondrus crispus, unbleached second experiment. 19·96 80·04 2·510 15·687

Laminaria digitata, or dulse tangle. 21·38 78·62 1·588 9·925

Rhodomenia palmata. 16·56 83·44 3·465 21·656

Porphyra laciniata. 17·41 82·59 4·650 29·062

Iridæa edulis. 19·61 80·39 3·088 19·300

Alaria esculenta. 17·91 80·09 2·424 15·150

From the above, we learn the important fact that the sea-weeds found on our coasts are amongst the most nutritious of vegetable substances, and that they, when dry, are even richer in nitrogenous matter than either oatmeal or Indian corn in the same state. The following are the chief varieties of algæ which are used as food by the dwellers on our coasts as well as on the continent:—Porphyra laciniata and VULGARIS, called laver in England, stoke in Ireland, and slouk in Scotland. Chondrus crispus, called carrageen or Irish moss, and also pearl-moss, and sea-moss. Laminaria digitata, known as the sea-girdle in England, tangle in Scotland, and red-ware in the Orkneys; and Laminaria saccharina, Alaria esculenta, or bladder-lock, called also henware, and honey-ware by the Scotch. Ulva latissima or Green Laver—Rhodomenia palmata or dulse of Scotland. Under the name of “marine sauce” the Laver was esteemed a luxury in London, where it may now occasionally be met with in the shops of provision merchants. The employment of the Chondrus crispus or Carrageen in the form of an aliment for consumptive and weakly persons, would seem from the analysis of it given above to be fully justified. In preparing the algæ for food, they must be soaked in water to remove the saline matter, and where they are possessed of a bitter flavour this may be removed by adding a little carbonate of soda to the water. They should then be stewed in water or milk till they are tender. The best flavourings are pepper and vinegar. See Jelly.

ALGARO′BA. Syn. Ca′′rob-tree, St. John’s Bread; Cerato′nia Sil′iqua, Linn. A leguminous tree of southern Europe, Palestine, and part of Africa. Pods (ALGAROBA BEANS), used for food, and to improve the voice; they contain a sweetish, nutritious powder, and are supposed to have been the ‘locusts’ on which St. John fed in the wilderness; their decoction has been used as a pectoral in asthma and coughs.

Algaroba or Algarovil′la. The astringent pods of prosopis pallida, p. siliquastrum, and Inga Marthæ (South American trees), bruised and more or less agglutinated by the extractive exudation of the seed and husks. They are used in tanning, for which purpose they have been strongly recommended; indeed that of Chili, and of Santa Martha (New Carthagena), is said to possess “four times the power of good oak bark” (Ure); and in dyeing are only inferior to oak-galls.

ALGONTINE. A mouth and tooth wash. An aqueous solution of nitrate of potassium, aromatised with oil of peppermint, tincture of myrrh, and tincture of cinnamon.

ALGOPHON (Bernhard, Salzburg). For pains in decayed teeth. A solution of ethereal oil of mustard (2 grms.) in spirit of cochlearia (30 grms.), coloured green by saffron and litmus. (Wittstein.)

AL′IMENT. [Eng., Fr.] Syn. Alimen′tum, L.; Nahrung, Speise, Ger. Food; nutriment; anything which nourishes or supports life.

ALIMENT′ARY Syn. Alimenta′′rius, L.; Alimentaire, Fr.; zur Nahrung gehörig, Ger. Pertaining to food or aliment; nutrimental; nourishing.

Alimentary Canal′. Syn. Alimentary duct; Cana′lis Alimenta′′rius, L. In anatomy, the cavity in the bodies of animals into which the food is taken for the purpose of being digested; the whole passage or conduit extending from the mouth to the anus. In some of the lower animals this is a simple cavity, with only one opening; when the same aperture which admits the food also gives egress to the excrementitious matter. In others it is a true canal, with both a mouth and an outlet. Another step, and we find this canal is divided into a stomach and intestines. In the higher grades, a mouth, pharynx, and œsophagus precede the stomach. Birds have one or two sacculi or crops added to the œsophagus. The stomach of the ruminants consists of four sacs or parts, each of which may be regarded as a separate stomach; that of the bottle-nose whale contains no less than seven of such sacs. The part below the stomach, forming the intestines, is also variously subdivided, complicated, and connected. In man, these subdivisions are termed—DUODENUM, JEJU′NUM, IL′EUM, CÆ′CUM, CO′LON, and REC′TUM; the lower end or orifice of the last being called the A′NUS. The existence of an alimentary canal is said to be the only true characteristic of an animal. Plants have no common receptacle for their food, nor canal for carrying away effete matter; but every animal, however low in the scale of being, possesses an internal cavity which serves it as a stomach.

Alimentary Sub′stances. Syn. Aliments; Mate′′ria alimenta′′ria, L. Substances employed as food.

ALIMENTA′TION. [Eng., Fr.] Syn. Alimenta′tio, L.; Nahrhaftigkeit, Ger. The act, process, power, or state of nourishing, or being nourished.

AL′IZARI. [Tur., ali-zari.] The commercial name of madder in the Levant.

ALIZARIN. C10H6O3 . 2H2O. Syn. Lazaric Acid. A red colouring matter obtained from madder.

Prep. 1. Exhaust madder with boiling water, and precipitate the decoction by sulphuric acid. Wash the precipitate, and, while yet moist, boil it with a concentrated solution of hydrate of aluminum in hydrochloric acid, and mix the solution with hydrochloric acid; red flakes of impure alizarin deposit. Dissolve this precipitate in alcohol or in dilute ammonia, and treat the solution with hydrate of aluminum. Boil the aluminum compound thus formed with carbonate of sodium, and, after freeing it from resinous impurities by digestion with ether, decompose it with hot hydrochloric acid. Wash the alizarin thus separated, dry it by simple exposure to air, and purify it by repeated crystallisation out of alcohol.

2. Sublime on a paper an alcoholic extract of madder. This method yields the purest alizarin.

Props. Red prisms; sublimes at 419° F.; odourless, tasteless, and neutral to test-paper; sparingly soluble in water, even at the boiling temperature; soluble in alcohol and ether; not decomposed by hydrochloric acid; dissolved, without decomposition, by strong sulphuric acid; soluble in solutions of the alkalies and their carbonates; acids precipitate alizarin from its alkaline solutions in orange-coloured flakes; alumina decolorises an alcoholic solution of alizarin, forming a red lake.

ALIZARIN, ARTIFICIAL. C14H8O4. This colour was first obtained by Graebe and Liebermann in 1869 from anthrachinon, an oxidation product of anthracen, this latter being a substance which is formed during the destructive distillation of coal-tar. These chemists converted anthracen into antichinon by means of nitric acid.

The crude anthracen is previously purified by treatment with benzoline (petroleum spirit), aided by heat, and by being subjected to the action of the centrifugal machine to fusion, and to sublimation.

According to the original method of preparing alizarin, the anthrachinon was first converted into a dibromide of anthrachinon by treatment with bromine, and this bromated compound, by further treatment either with caustic potash or soda at a temperature of 180° to 200° C., converted into alizarin-potassium (or alizarin-sodium if caustic soda has been used), from which the alizarin is set free by means of hydrochloric acid.

Alizarin is now procured from anthrachinon by treatment at a temperature of 260° C., with concentrated sulphuric acid of 1·84 sp. gr., the anthrachinon being converted into a sulpho-acid; this acid is next neutralised with carbonate of lime, the fluid decanted from the deposited sulphate of lime, and carbonate of potash added to it, with the object of throwing down all the lime. The clear liquid is then evaporated to dryness, the resulting saline mass is converted into alizarin-potassium by heating it with caustic potash. From the alizarin-potassium thus obtained the alizarin is set free by the aid of hydrochloric acid.

In another method the preparation of anthrachinon is avoided, and anthracen employed directly, by first converting it, by means of sulphuric acid and heat, into anthracen sulphonic-acid. After having been diluted with water, the solution of this acid is treated with oxidising agents (peroxides of manganese, lead, chromic acid, nitric acid), and the acid fluid is afterwards neutralised with carbonate of lime. When peroxide of manganese has been used, the manganese is also precipitated as oxide. The oxidised sulpho-acid having been previously converted into a potassium salt, the latter being heated with caustic potash, alizarin is obtained. The details of these two processes will be found set forth in the terms of the patent taken out by Messrs Caro, Graebe and Liebermann, further on.

The following method of preparing alizarin from anthracene paranaphthalene and their homologues is by Girard. The material used is that which distils between 290° and 360°; it is purified by distillation and pressure, the portion which passes over, between 300° and 305°, being collected separately. This mixture is treated with potassium chlorate and hydrochloric acid, whereby it is converted into tetra-chlorinated products. These are oxidised either by nitric acid in the water bath, or by a metallic oxide (red or brown oxide of lead), and sulphuric or acetic acid. In the first place a mixture of dichloranthraquinine and chloride of chloroxyanthranyl are obtained. These substances are treated in presence of a metallic oxide (oxide of zinc, oxide of copper, or litharge), with an alcoholic solution of sodium acetate. The metallic oxide removes the last atom of chlorine from the sodium chloroxyanthranilate, and converts it, like the dichloranthraquinine, into alizarin. The purification is effected by means of benzine, petroleum, &c., which dissolve out the foreign matters, and by successive precipitation from the alkaline solutions by mineral acids. The foreign matters may also be separated by means of a little alum, when it is necessary to work with neutral potash or soda salts.

Another method for the preparation of alizarin has been patented by Dale and Schorlemmer. It is as follows: 1 part of anthracen is boiled with 4 to 10 parts of strong sulphuric acid, then diluted with water, and the solution neutralised with carbonate of calcium, barium, potassium, or sodium. The resulting sulphates having been removed by nitration or crystallisation, the solution is heated to between 180° and 260° with caustic potash or soda, to which a quantity of potassium nitrate or chlorate has been added, about equal in weight to the anthracen, as long as a blue-violet colour is thereby produced. From this product the alizarin is separated in the usual way by precipitation with an acid. Several other patents have been taken out for the preparation of artificial alizarin.

The specification of Messrs Caro, Graebe, and Liebermann, and dated June 25th, 1869, was the first which was taken out in England. We quote it here because it enters more fully into detail than any of the others.

“Our invention is carried into effect by means of either of the two processes which we will proceed to describe.

“In the one process we proceed as follows—We take about one part by weight of anthraquinone and about three parts by weight of sulphuric acid of about specific gravity of 1·488, and introduce the same into a retort, which may be made of glass, or porcelain, or of any other material not easily acted upon by sulphuric acid, and the contents are then to be heated up to about 260° Centigrade, and the temperature is maintained until the mixture is found no longer to contain any appreciable quantity of unaltered anthraquinone. The completion of this operation may be ascertained or tested by withdrawing a small portion of the product from time to time, and continuing the operation at the high temperature until such product upon being diluted with water is found to form a substantially perfect solution, thereby indicating that the anthraquinone has become either entirely or in greater part converted into the desired product. The products thus obtained are then allowed to cool, and are diluted with water; carbonate of lime is then added in order to neutralise and remove the excess of sulphuric acid contained in the solution; the mixture is then filtered, and to the filtrate carbonate of potash, or carbonate of soda, by preference in solution, is to be added until carbonate of lime is no longer precipitated; the mixture is then filtered, and the clear solution is evaporated to dryness, by which means the potash or soda salts of the sulpho-acids of anthraquinone are obtained, and which are to be treated in the following manner:—We take about one part by weight of this product, and from two to three parts by weight of solid caustic, soda, or potash; water may be added or not, but by preference we add as much water as is necessary to dissolve the alkali after admixture; we heat the whole in a suitable vessel, and the heating operation is continued at a temperature of from about 180° to 260° Centigrade, for about one hour, or until a portion of the mixture is found upon withdrawing and testing it to give a solution in water, which being acidulated with an acid, for example, sulphuric acid, will give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, the resulting products are then dissolved in water, and we either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin, by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring matters thus obtained are collected in a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise.

“In carrying out our other process we proceed as follows:—We take about one part by weight of anthracene and about four parts by weight of sulphuric acid of specific gravity of about 1·848, and the mixture being contained in a suitable vessel, is heated to a temperature of about 100° Centigrade, and which temperature is to be maintained for the space of about three hours; the temperature is then to be raised to about 150° Centigrade, which temperature is to be maintained for about one hour, or until a small portion of the product when submitted to the two subsequent processes hereinafter described is found to produce the desired colouring matters; we then allow the result obtained by this operation to cool, and dilute it with water, by preference in the proportion of about three times its weight. To the solution thus obtained we add for every part of anthracene by weight which had been employed in the previous operations, from about two to three parts by weight of peroxide of manganese, preferring to employ an excess, and we boil the whole strongly for some time, and in order fully to ensure the desired degree of oxidation the mixture may be subsequently concentrated, and by preference be evaporated to dryness, and the heat be continued until a small portion of the oxidised product, when submitted to the subsequent processes hereinafter described will produce the desired colouring matters. We then neutralise and remove the sulphuric acid contained in this mixture, and at the same time precipitate any oxides of manganese that may be held in solution, by adding an excess of caustic lime, which we use by preference in the form of milk of lime, and we add the same until the mixture has an alkaline reaction. We then filter, and add to the filtrate carbonate of potash or soda, until there is no further precipitation of carbonate of lime. The solution is then filtered and evaporated to dryness, and we thus obtain the potash or soda salts of what we call the sulpho-acids of anthraquinone.

“In effecting the conversion of the oxidised products thus obtained into colouring matters, or into what we call artificial alizarin, we proceed as follows:—We take one part by weight of this product, and from two to three parts by weight of solid caustic soda or potash, and water may be added or not, but by preference we add as much water as may be necessary to dissolve the alkali. After admixture we heat the whole in a suitable vessel, and continue the heating operation at a temperature of about 180° to about 260° Centigrade for about one hour, or until a portion of the mixture is found to give a solution in water, which upon acidulation with an acid, for example, sulphuric acid, is found to give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, we then dissolve the product in water, and either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring matters thus obtained are collected on a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise.

“Instead of acting upon anthracen by means of sulphuric acid of the density before mentioned, fuming sulphuric acid may be employed, but we prefer to use the ordinary kind before described.

“In order to effect the process of oxidation, before referred to, other oxidising agents may be used in the place of the oxide of manganese, before mentioned, such, for example, as perioxide of lead, or chromic, nitric, or other acids capable of effecting the desired oxidation may be employed.”

Mr W. H. Perkin’s patent is similar in principle to that of Messrs Caro, Graebe, and Liebermann, and is dated only one day later.

The following is an outline of a patent taken out in France in May, 1869, by MM. Brœnner and Gutzkon, for the manufacture of artificial alizarin. One part of anthracen is heated with two parts of nitric acid, sp. gr. 1·3 to 1·5. The anthraquinone thus produced is washed and dissolved at a moderate heat in sulphuric acid. Mercuric nitrate is now added, which converts the anthraquinone into alizarin, The mass thus formed is dissolved in an excess of alkali, which precipitates the oxide of mercury, and retains the colouring matters in solution. The alkaline liquor is decanted and neutralised with sulphuric acid, and the precipitate thus formed is washed and collected. If not quite pure the treatment with alkali must be repeated. (The complete specification of this patent is published in the ‘Moniteur Scientifique,’ vol. xi, p. 865.)

In England a large quantity of artificial alizarin is manufactured by the process of Mr Perkin, and is used as a substitute for madder and madder extract, in Turkey red dyeing and topical styles. The largest makers of artificial alizarin on the continent are Messrs Gessert Frères, of Ebelfort, Messrs Maister, Lucius and Co., of Hæchst, near Frankfort, and the Badische Anilin und Soda Fabric, Mannheim.

The following recipes for printing with artificial alizarin are extracted from Mr Crookes’ ‘Practical Handbook of Dyeing and Calico Printing’:

Reds.

5 lbs. alizarin paste (10 per cent.);

16 lbs. thickening;

1 lb. acetate of alumina, at 15° Tw.;

⁄2 lb. acetate of lime, at 25° Tw.

Pinks.

The above diluted with 2 or 3 parts of thickening.

For double printing, when deep red is printed on first, the goods must be steamed one hour before the second printing takes place. After the second printing the goods are again steamed for one hour, and aged for twenty-four hours; they are then passed through one of the following baths, at from 120 to 140 F., remaining in the bath not longer than 1 to 1⁄2 minute:—

250 gals. water;

60 lbs. chalk;

3 lbs. tin crystals.

Or, 250 gals. water;

40 lbs. chalk;

10 lbs. arseniate of soda.

The goods are then washed, and cleaned as follows:—

Take, for 10 pieces of fifty yards each,—

1st. Soaping at 120° F., 3 lbs. soap;

⁄4 lb. tin crystals.

2nd. Soaping at 160° F., 3 lbs. soap;

3rd. Soaping at 175° F., 3 lbs. soap.

Wash between each soaping.

Red for Mosaics.

8 lbs. alizarin paste (10 per cent.);

10 quarts thickening;

9⁄2 oz. nitrate of alumina, at 23° Tw.;

19 oz. acetate of alumina, at 15° Tw.;

13 oz. acetate of lime, at 25° Tw.

Or, 10 lbs. alizarin paste (10 per cent.);

10 quarts thickening;

13 oz. nitrate of alumina, at 23° Tw.;

19 oz. acetate of alumina, at 15° Tw.;

16 oz. acetate of lime, at 25° Tw.

Another Red without Oil.

8⁄2 lbs. alizarin paste (10 per cent.);

9⁄2 lbs. acetic acid, at 12° Tw.;

3⁄2 lbs. wheat flour;

5 pints water.

Boil well and stir till cold; then add—

1 lb. acetate of lime, at 29° Tw.;

2 lbs. nitrate of alumina, at 23° Tw.;

3 lbs. hyposulphite of lime, at 13° Tw.

Purple.

3 lbs. alizarin paste (10 per cent.);

10 quarts purple thickening;

6 oz. pyrolignite of lime, at 18° Tw.;

12 oz. acetate of lime, at 25° Tw.

The printed goods are steamed for an hour or two, and then aged from twenty-four to thirty-six hours. They are then padded in the chalk and arseniate of soda bath; after which they are washed and soaped in a single soap-bath without tin crystals; and, if needful, cleaned in a weak solution of bleaching powder.

Thickening for Reds.

12 lbs. wheat starch;

40 quarts water;

4 quarts acetic acid, 9 Tw.;

1⁄4 lbs. gum tragacanth;

2 lbs. olive oil.

Boil well together, and stir till cold.

Thickening for Purple.

10 lbs. starch;

27 quarts water;

3 quarts acetic acid;

1⁄8 lbs. gum tragacanth;

2 lbs. olive oil.

Boil well together, and stir till cold.

The mordants in the above recipes are prepared as fellows:

Acetate of Alumina.

Stir 30 lbs. of hydrate of alumina into six quarts of acetic acid, warm, filter, and reduce to the specific gravity required.

The hydrate of alumina is prepared by dissolving 72 lbs. of alum in 100 gals. of water, and 62 lbs. soda in 100 gals. of water. The two solutions are mixed, this precipitate is washed eight times by decantation, collected on a filter and pressed. It must be dissolved on the filter before it gets dry.

Nitrate Of Alumina.

2 lbs. nitrate of lead;

2 lbs. alum;

2 quarts water.

Dissolve and filter off the liquid from the precipitate, and dilute to proper standard.

The reds are turned more yellow by nitrate than by acetate of alumina, and when the former is used more acetate of lime is taken in addition.

Acetate of Lime.

A solution of acetate of lime at 25° Tw. contains 25 per cent. of acetate of lime; generally ⁄10th of the weight of alizarin paste is required; but with a fresh quantity of alizarin it is safer to ascertain, on a small scale, the amount needed.

Brown.

13⁄4 lbs. alizarin paste (15 per cent.);

9 quarts thickening;

2 lbs. nitrate of alumina, at 29° Tw.;

15 oz. acetate of alumina, at 19° Tw.;

15 oz. red prussiate potash, dissolved in

water;

1 lb. 1 oz. acetate of lime, at 29° Tw.

To obtain a yellower shade, for every quart of mixed colour, 1 oz. bark liquor, at 30° Tw., may be added.

Old spoiled red colours may be advantageously used for browns by adding per quart, ⁄4 oz. to 1 oz. red prussiate, dissolved in water.

ALKALI. Syn. Alkali, Fr.; Langensalz, Ger. This word has been used in various senses, but is now usually applied to four substances only, viz. the hydrates of potassium, sodium, lithium, and ammonium (the latter being supposed to exist in the aqueous solution of ammonia). In a more general sense it is applied to the hydrates of barium, strontium, and calcium, which, for the sake of distinction, are called the alkaline earths. The following properties are characteristic of the alkalies:—(1) They are soluble in water, the alkalies proper more so than the alkaline earths. (2) They change the hue of many vegetable colouring matters; thus, they turn reddened litmus blue, yellow turmeric brown, and syrup of violets and infusion of red cabbage green. (3) They neutralise the strongest acids. (4) They precipitate most of the heavy metals from solutions of their salts as hydrates or oxides. (5) They saponify the fixed oils and fats. (6) They exert a caustic or corrosive action on animal and vegetable substances.

ALKALI ACTS. The principal alkali Act is the 26 and 27 Vict., c. 24, amended by 37 and 38 Vict., c. 43, the amended Act having come into operation in 1875.

Every alkali work must be carried on so as to ensure the condensation of not less than 95% of muriatic acid evolved therein; and it must be so condensed that in each cubic foot of air, smoke, or chimney gases, escaping from the works into the atmosphere, there is not contained more than one fifth part of a grain of muriatic acid. Penalty for first conviction, £50; for second and other offences, £100, or less (26 and 27 Vict., c. 124, s. 4; 37 and 38 Vict., c. 43, s. 4).

The owner of every alkali work is also bound “to use the best practicable means of preventing the discharge into the atmosphere of all other noxious gases arising from such work; or of rendering such gases harmless when discharged.”

The noxious gases are defined to be sulphuric acid, sulphurous acid (except that arising from the combustion of coals), nitric acid, or other noxious oxides of nitrogen, sulphuretted hydrogen and chlorine (37 and 38 Vict., c. 43, ss. 5 and 8).

The owner is liable for any offence against the Alkali Acts, unless he prove that the offence was committed by some agent, servant, or workman, and without his knowledge, in which case the agent, &c., is liable (26 and 27 Vict., c. 124, s. 5).

Every alkali work must be registered; penalty for neglect £5 per day (ibid., s. 6).

Powers are given to owners to make special rules for the guidance of their workmen (ibid. s. 13).

ALKALIM′ETRY. Syn. Alkalime′tria, L.; Alcalimétrie, Fr. In chemistry, the estimation of the strength of the commercial alkalies; the art or process of determining the quantity or proportion of pure caustic alkali, or of its carbonate, in any given sample or simple solution. It is the reverse of ‘acidimetry,’ and it should be understood that it does not apply to alkalies occurring under any other form or condition than those just mentioned. Alkalimetric assays are now also frequently and conveniently extended to the estimation of the alkaline earths and their carbonates, as hereafter noticed.

Alkalimetrical processes. These, like those of ‘acidimetry,’ are for the most part founded on—the capacity of the bases to saturate acids—the estimation of the quantity of dry carbonic acid liberated from a given weight of an alkaline carbonate under the influence of a stronger acid; and, in the case of the pure alkalies, the sp. gr. of their solutions. From any one of these results the exact amount of alkali, or of alkaline carbonate, present in a sample, is easily found or calculated. These processes are, indeed, precisely similar to those described under Acidimetry; but here the unknown quantity sought is the alkali, instead of the acid.

Assay. The SAMPLE is drawn from as near the centre of the cask containing the alkali as possible, and at once placed in a wide-mouthed bottle, which is then closely corked up and numbered. Before proceeding to the assay, the contents of the bottle are thrown on a piece of dry paper, the lumps crushed small, and the whole reduced to coarse powder as rapidly as possible. The number of grains required for the trial are then at once weighed, placed in a phial or small glass tube, and agitated with about ⁄2 oz. of hot water. After a short time allowed for repose, the clear liquid is poured off into a beaker-glass or other vessel in which the trial is to be made. This process is repeated with a second and a third quantity of water, or until nothing soluble remains, shown by the last washings not affecting the colour of turmeric paper. The greatest care must here be taken not to waste the smallest portion of the liquid, which would render the results inaccurate.

To the solution in the beaker-glass a little solution of litmus is added, unless the acid is tinted with it when it is unnecessary. The solution is now heated until near its boiling point, and a piece of white paper or porcelain put behind it, to better show up the changes of colour. The alkaline solution is now treated with the standard test-acid, which is poured carefully from an alkalimeter or Mohr’s burette, until the solution, after turning a purple red, suddenly assumes a pink colour. Neutralisation being thus effected, the operator allows the sides of the alkalimeter or burette to drain, and then either ‘reads off’ the number of divisions which have been consumed, or (if using the test-acid by weight) determines the quantity by again weighing the alkalimeter. The common practice is to allow two drops (= ⁄5th of an alkalimetrical division by VOLUME, or 2 gr. by WEIGHT) for over-saturation, which is, therefore, deducted from the ‘observed quantity’ of the test-liquor employed.

In testing solutions of the PURE or CAUSTIC ALKALIES, the colour, on neutralisation, suddenly changes from blue to pink or red, without any intermediate vinous or purple colour being produced.

The quantity of test-acid used gives the absolute or per-centage composition of the sample examined, according to the constitution of the test-acid used.

Standard Acids. The various test-acids in use as described below, each being used by different operators as they think best.

The most convenient test-acid, or normal solution, both for commercial and chemical assays, is perhaps dilute sulphuric acid, which, when intended to be used VOLUMETRICALLY, has the sp. gr. 1·032 at 60° Fahr., and contains in 100 alkalimetrical divisions 1000 water-grains measure, or 1 litre, exactly 49 gr. (or grammes) of sulphuric acid; and when intended to be used GRAVIMETRICALLY, or by weight, has the sp. gr. 1·033, and contains in 1000 gr. (or grammes) weight exactly 49 gr. (grammes) of sulphuric acid; and, in both cases, consequently corresponds to 1 equiv. of every other base. These dilute acids are easily prepared by mixing 1 part of the concentrated acid with 11 or 12 parts of distilled water; the precise quantity depending on the strength of the acid employed, and must be so arranged that 1000 grains shall exactly neutralise 1000 grains of water containing 53 grains of pure anhydrous sodium carbonate.

This acid (as well as all those hereafter mentioned) may be kept faintly tinged with litmus, which is often more convenient than tinging the alkaline solution at the time of making the assay.

It will at once be seen that every alkalimeter division of the first of the above acids, and every 10 gr. of the second, represent the ⁄100th part, or 1% of alkali whenever the equivalent weight of the latter is taken for the assay. Every 1-10th part of an alkalimeter-division (or every drop), and every grain weight (when a Schüster’s alkalimeter is employed) then respectively represents the ⁄10 of 1%; and the result sought is obtained without the necessity of any calculation.

This is obvious—for if the equivalent of a pure alkali or of its carbonate (i. e. one of 100%) requires an equiv. (100 alkalimeter-divisions, or 1000 gr.) of test-acid to saturate it, an alkali or alkaline carbonate of 75%, 50%, or 25%, will respectively require only 75, 50, or 25 divisions, or 750, 500, or 250 gr.; and so of other strengths in proportion. The only precaution necessary is always to take the standard weight for the assay answering to the equiv. of the denomination of the per-centage result sought. Thus, in testing a carbonate of potash, we may either wish to determine its per-centage richness in ‘dry carbonate,’ or in ‘pure potassa,’ the latter being usually the case. To obtain the first, we must take 69 gr. for the assay; and to obtain the second, 47 gr. With CAUSTIC ALKALIES, or mixtures containing them, the weight, in grains, taken for the assay, must always correspond to the equiv. of the pure base. See Table II, at the end of this article.

In commercial assays, when 100 gr. (or some aliquot part thereof) are taken for trial, the per-centage result is obtained from the number of alkalimeter-divisions, or the number of grains, of the test-acid consumed, by the common Rule of Proportion. Thus:—A crude sample of potash having taken 90 alkalimeter-divisions of test-acid to neutralise it, would contain—

100 : 47 :: 90 : 42·30%

or nearly 42⁄3 per cent. of pure potassa. If only 50, 25, or 20 gr. are tested, the result must, of course, be double, quadruple, &c., as the case may be. Or the third term of the proportion may be multiplied by the denominator of the fraction representing the aliquot part. This, in the case of 50 gr. (repeating the above example), would be—

10 : 47 :: 45 × 2 : 42·30%

as before; but even these easy calculations may be simplified, as is shown below.

One of the advantages, and not the least, attending the use of test-acids corresponding to equivalents, is, that by means of the simple Rule of Three, the per-centage quantity of alkali may be found whether 100 or any other number of grains have been submitted to trial. For—The weight of the sample tested (in grains) bears the same relation to the equivalent weight of the alkali under examination, that the number of alkalimeter-divisions or of the grains of test-acid consumed do to the per-centage of alkali sought. Thus, with a sample of 33 gr. of pearlash taking 35 alkalimeter-divisions or 350 grains (every 10 gr. being = 1%) of test-acid for neutralisation, this would be—

33 : 47 :: 35 : 49·85%

or nearly 50 per cent. of pure potassa. By substituting the equiv. of the dry carbonate of potash (69), for that of pure potassa used above, the quantity of that article corresponding to the same weight of the pure alkali may be at once found. Repeating the last example this will be—

33 : 69 :: 35 : 73·18%

or nearly 73⁄4 per cent. The same applies to all the alkaline bases and their carbonates.

For commercial purposes, there is used, amongst others, an empirical solution, as a test-acid for potassa, soda, and ammonia, to save the necessity of calculation.

This is dilute sulphuric acid having a sp. gr. of about 1·071; 100 alkalimeter-divisions (1000 water-grains measure) exactly saturate 100 gr. of pure potassa, or 113 gr. of anhydrous carbonate of soda. The number of measures consumed, read off by mere inspection from the scale of the alkalimeter, gives the exact per-centage of alkali in the sample examined, for POTASH; and by multiplying it by ·66, that for SODA also. By employing ·362 as the multiplier, it gives the like result for AMMONIA. In fact, occasionally, in order to save the necessity of any calculation, two ‘test-acids’ are frequently employed—the one for potash and the other for soda.

These are made by diluting sulphuric acid to a sp. gr. of near 1·071 and 1·086 respectively; 1000 grains, by measure, of the first neutralising exactly 100 grains of pure potassa, or 113 of pure anhydrous soda carbonate, and the latter neutralising exactly 100 grains of pure soda, or 171 gr. of pure anhydrous sodium carbonate.

There is another system of preparing standard acids by means of a Faraday’s alkalimeter. A strong acid is prepared by diluting sulphuric acid to a sp. gr. of 1·1268 at 60°, and 455·7 grains exactly neutralise 100 of anhydrous carbonate of soda.

The glass tube here referred to, and known as Faraday’s ALKALIMETER, is graduated centesimally, in the usual manner; but opposite the numbers 22·1, 48·62, 54·43, and 65, are cut the words ‘soda,’ ‘potassa,’ ‘carbonate of soda,’ and ‘carbonate of potassa,’ to indicate the quantity of the test-acid to be employed for each of these substances. (See engr.) It is used by pouring the test-liquor into it until it reaches the line marked against the alkali, or carbonate, under examination, the remaining divisions being filled up with pure water, and the whole well mixed by placing the thumb on the orifice of the tube and shaking it well. The measure of the resulting dilute acid must then be very carefully observed, and more water added, if required, to bring it up to the zero (0) or 1000 gr. on the scale; careful agitation being again employed as before. The test-acid thus prepared is then added, with the usual precautions, to the sample until exact neutralisation is effected. The quantity consumed for this purpose, read off from the graduated scale, expresses the exact per-centage of the pure ALKALI, or of its CARBONATE, as the case may be, contained in the sample examined, provided 100 gr. have been taken for the assay.

Another method sometimes used is that of M. Mohr, and practised as follows:—The alkaline solution, slightly coloured blue with litmus, is strongly super-saturated with a standard acid (sulphuric or oxalic) of known strength, supplied from an alkalimeter in the usual manner; the last traces of carbonic anhydride being removed by boiling, shaking, blowing into the flask, and, finally, sucking out the air. A standard solution of caustic soda (of a strength exactly corresponding to that of the test-acid already used) is now cautiously added, drop by drop, until the colour, rendered yellowish-red by the acid, just appears of a light blue. The difference between the quantity of the solution of the test-alkali and of the test-acid consumed, expresses the exact quantity of acid neutralised by the alkali, and hence also its strength.

Besides the above methods, the alkaline carbonates are analysed, by the loss of carbonic anhydride (carbonic acid) they suffer, by being decomposed by a strong acid. The best method in use is that of MM. Fresenius and Will, and depends on the same principle, and is performed in a similar manner and in a similar apparatus to that described under Acidimetry; the only difference being that here the uses of the small tube (e) is dispensed with, and that the alkali is tested under the form of carbonate, instead of bicarbonate.

Oper. The smaller flask (B) is about half filled with concentrated sulphuric acid, and the sample of alkali, in solution (under the form of carbonate), being placed in the larger flask (A), water is added until it is about one third full. The tubes are then fitted into the apparatus quite air-tight; the end of the tube (b) is fastened with a piece of wax, and the whole is very carefully weighed. The apparatus is now removed from the scales, and a perforated cork, or a small piece of india-rubber tube, being temporarily applied to the end of the tube (h), a few bubbles of air are sucked out of the flask (B) by means of the lips; the consequence of which is, that on removing the mouth the acid in (B) ascends to a certain height in the tube (c). If in a short time this little column of liquid maintains its height in the tube, it is a proof that the apparatus is perfectly air-tight, and as it should be. Suction is now again cautiously applied to the tube (h) and a little of the acid in (B) made to flow over into the flask (A), the quantity being proportionate to the vacuum produced by suction, and capable of being regulated at will. No sooner does the acid come into contact with the carbonate in the flask (A) than the evolution of carbonic acid commences, and this, from the construction of the apparatus, having to pass through the concentrated sulphuric acid, is rendered quite dry before it can escape by the tube (d) into the atmosphere. Whenever the effervescence flags, a little more acid is sucked over, until the whole of the carbonate is decomposed; after which an additional quantity is made to pass into (A), so as to raise the temperature considerably, for the purpose of expelling all the gas absorbed by the fluid during the operation. As soon as this is effected, the wax is removed from the aperture (b), and suction applied to (h), until all the carbonic acid in the apparatus is replaced by atmospheric air. The whole is now allowed to cool, and (together with the piece of wax removed) is again accurately weighed. The loss of weight gives the exact amount of dry carbonic anhydride, or anhydrous carbonic acid, which was contained in the specimen, from which the weight of PURE ALKALI is readily estimated, as every 22 gr. of dry carbonic acid gas evolved represents exactly 31 gr. of pure SODA, 47 gr. of pure POTASSA, &c. &c.; these numbers being the equivalents of the respective substances from which the per-centage strength may be found by the rule of proportion, as before explained.

Thus, in the case of a 100-gr. sample of carbonate of soda which has lost 15⁄4 gr. of carbonic acid, by the assay, this would be—

22 : 31 :: 15⁄4 : 21·48%

or nearly 21⁄2 per cent. of pure soda. If 53, the equiv. of anhydrous carbonate of soda, be taken, instead of 31 (the eq. of pure soda), the answer would have been, in the terms of that substance, 36·748%, or nearly 36⁄4 per cent. When an aliquot part of 100 gr. has been taken for the assay, either the result, or the third term of the proportion, must, of course, he multiplied by the denominator and divided by the numerator of the fraction representing such aliquot part.

By multiplying the weight of carbonic anhydride lost, by the numbers opposite the names of the respective alkalies and their carbonates in the second column of the following Table the equivalent per-centage value of the carbonates examined may be obtained in terms corresponding to the various denominations named therein, when 100 gr., or any aliquot part of 100 gr., have been tested; the result, in the latter case, being, of course, multiplied as before.

By taking certain standard weights for the assay, the quantity of carbonic acid evolved may be made to furnish the per-centage strength or value of the specimen in the terms of either the pure or carbonated alkalies, whether in their anhydrous or hydrated state. The numbers in the second column of the following Table represent the quantity in grains and decimal parts of each of the substances named in the first column, equivalent to one grain of carbonic anhydride. These numbers, as already mentioned, may be employed as factors for converting any numbers representing grains of that acid into the equivalents of these substances, true to 4 places of decimals; and further, they furnish us with the data for determining the exact number of grains which must be tested, so that the loss of weight in carbonic anhydride shall at once give us the per-centage richness of the sample in the terms of the denomination for which it is taken. The numbers in the third column of the Table, formed by simply moving the decimal point of the numbers in the second column one figure further to the right, indicate the weights to be taken for the assay, so that the loss of weight, reckoned in tenths of a grain, exactly represents the per-centage strength in the terms sought. The weights corresponding to the numbers in the fifth column give the same results, provided the loss of weight is reckoned in quarter-grains; those in the sixth column effect the same when the loss of weight is reckoned in half-grains; whilst those in the last column require that the gas eliminated should be counted in grains, and are simply the numbers in the second column of the Table multiplied by 100, or reproduced by moving the decimal point two figures to the right.

Table I.—Multipliers and Standard Weights for the Principal Alkalies and their Carbonates. (Cooley.)

NAMES, &c. Factors or Multipliers for converting the weight of carbonic acid expelled into real strengths. Quantity (in grains) to be taken, so that the per-centage value of the sample tested shall be shown in the terms of any of the denominations given, by the weight of the evolved Carbonic Acid reckoned—

In tenths of a grain.

Whole numbers and decimals. Nearest common numbers. in quarter-grains. in half-grains. in grains.

Ammonia (pure, gaseous) ·77273 7·727 7⁄4 19⁄3 38⁄8 77⁄0

Carbonate of ammonia (neutral, anhydrous) 1·77273 17·727 17⁄4 44⁄16 88⁄8 177⁄4

Carbonate of ammonia (neutral, crystallised) 1·9773 19·773 19⁄4 49⁄16 98⁄8 197⁄4

Sesquicarbonate of ammonia (translucent) 2·6818 26·818 26⁄16 67⁄10 134⁄10 268⁄5

Bicarbonate of ammonia (crystallised) 3·5909 35·909 35⁄10 89⁄16 179⁄8 359⁄10

Potassa (anhydrous) 2·1364 21·364 21⁄2 53⁄2 107 213⁄8

Hydrate of potassa 2·54546 25·455 25⁄11 63⁄8 127⁄4 254⁄2

Carbonate of potassa (anhydrous) 3·1364 31·364 31⁄8 78⁄2 157 313⁄2

Carbonate of potassa (granulated) 3·7727 37·727 37⁄2 94⁄10 188⁄8 377⁄4

Carbonate of potassa (crystallised) 3·9545 39·545 39⁄8 99 198 395⁄2

Bicarbonate of potassa (crystallised) 4·5454 45·454 45⁄2 113⁄4 227⁄2 454⁄2

Soda (anhydrous) 1·4091 14·09 14⁄10 35⁄4 70⁄2 141

Hydrate of soda 1·8182 18·182 18⁄5 45⁄2 91 182

Carbonate of soda (anhydrous) 2·4091 24·091 24⁄10 60⁄4 120⁄2 241

Carbonate of soda (crystallised) 6·5 65· 65 162⁄2 325 650

Sesquicarbonate of soda (dry; theoretical) 2·9091 29·091 29⁄10 72⁄2 145 290

Sesquicarbonate of soda (Ph. L., 1836) 3·7273 37·273 37⁄4 93⁄4 186⁄2 373

Sesquicarbonate of soda (average commercial) 3·7954 37·954 38 94⁄8 189⁄4 379⁄2

Bicarbonate of soda (crystallised) 3·8182 38·182 38⁄5 95⁄2 191 382

Lithia (pure, anhydrous) ·6818 6·818 6⁄16 17⁄20 34⁄10 68⁄5

Baryta (pure, caustic) 3·4773 34·773 34⁄5 86⁄8 173⁄8 347⁄4

Lime (pure, caustic) 1·2727 12·727 12⁄4 31⁄4 63⁄8 127⁄4

Magnesia (pure, anhydrous) ·90909 9·091 9⁄11 22⁄4 45⁄2 91

In this ingenious method of alkalimetry it is absolutely necessary that the whole of the alkali in the specimen tested should be in the state of neutral carbonate. If a sample of potash contains any caustic alkali (as the potashes and pearlash of commerce generally do), Fresenius and Will direct it, previously to being tested, to be triturated with its own weight of pure quartzose sand, and about one third of its weight of carbonate of ammonia; and the resulting mixture, placed in a small iron capsule, or a porcelain crucible, to be moistened with water, and exposed to a gentle heat until it becomes quite dry, and all the ammonia is expelled. If the sample contains any bicarbonate or sesquicarbonate, it must be heated to dull redness before being placed in the apparatus and tested. In the case of crude soda (particularly soda ash), the proportion of carbonate of ammonia should be equal to at least one half the quantity operated on. With both alkalies, if the sample contains sulphides, sulphites, or hyposulphites, the same method is to be followed, except that solution of ammonia, instead of water, is to be employed for moistening the powder. To remedy the error which would arise from the apparent amount of carbonic anhydride liberated during the assay, being swelled by the disengagement of ‘sulphuretted hydrogen’ or sulphurous acid from these substances, a small quantity of neutral (i. e. yellow) chromate of potash may be added to the alkaline solution in the flask (A); by which they will be converted into sulphates, sulphur, and water, which will remain in the apparatus, the carbonic acid only being evolved. “As most sorts of soda of commerce contain one or other of the substances (just) named, and as it is far more simple to add at once some chromate of potassa to the soda solution, than to test the latter for either of the three salts, it is always advisable to make it a rule, in the examination of SODA, to add some chromate of potassa.” (Fresenius.)

If the sodium or other carbonate under analysis contains much chloride, the addition of more sulphuric acid than necessary must be avoided, and the carbonic anhydride expelled by gently heating over a warm bath, and not by the addition of excess of acid.

To obviate the difficulties, and to give greater precision and delicacy to volumetrical assays, the instrument known as Mohr’s ALKALIMETER, or Mohr’s BURETTE, and which is figured in the margin, may be employed. By means of it the test-acid in the graduated tube (a) may be added to the alkaline solution in (f), in any quantity at a time, however minute, by merely pressing the handles of the clamp (d) with the thumb and finger. The terminal tube (e) has its lower orifice very small, and it is connected with the burette by means of a small piece of vulcanised india-rubber tube, on which the clamp (d) acts. (See engr.) The inner cylindrical part of the arm (b) is lined with cork, to prevent injury to the glass burette, and to hold it the more firmly.

Generally the alkali in the specimen examined may be in either the caustic or carbonated state, or it may consist of any mixture of caustic alkali, or carbonates; but it is absolutely necessary for accurate results, that it should be free from sulphides, sulphites, and hyposulphites, as sulphuric acid acts upon these substances as well as on carbonates. The presence of chlorides does not interfere with the accuracy of the assay, unless a higher degree of heat is employed than that necessary for the expulsion of the absorbed carbonic acid. The SODA-ASH of commerce generally contains all these substances besides common salt, sulphate of soda, and insoluble matter, which do not interfere. Rough samples of POT-ASHES and PEARL-ASH also generally contain some sulphides, though not a large quantity. Various plans have been proposed to avoid this source of error. The best is that of MM. Fresenius and Will, given above, in which the value of the carbonates is estimated by their yield of carbonic anhydride.

The difference between an assay of a sample of the unprepared alkali and of another which has been treated as above, indicates the quantity of impurities contained in them under the forms just referred to. The presence of these substances in the commercial alkalies may be detected by the following tests:—

Sulphides. The addition of sulphuric acid causes the evolution of an odour like that of rotten eggs. The sample in solution yields a black precipitate with acetate of lead. But the most delicate test is the splendid violet-blue colour with nitro-prusside of sodium.

Sulphites and Hyposulphites. A solution of the alkali, insufficient for saturation, being added to sulphuric acid tinged reddish yellow with bichromate of potash, occasions a greenish tinge (owing to the formation of oxide of chromium), when these are present. Hydrochloric acid added to a clear solution, after some time, causes a turbidity and odour of sulphurous anhydride.

Chlorides yield a copious curdy precipitate with nitrate of silver, soluble in ammonia, and reprecipitated by excess of nitric acid.

The amount of pure caustic alkali in a sample of alkali is best determined by Fresenius’s method, as follows:—The total amount of pure alkali, both caustic and carbonated, expressed in per-cents. of carbonate of soda or carbonate of potassa, is ascertained by any of the usual methods. The apparent quantity of alkali per cent. is then determined, without previous treatment of the sample with carbonate of ammonia, by the method of Will and Fresenius (p. 86). The difference between the results indicates the per-centage of dry caustic alkali present; or if the volumetric method be in use, it can be often fairly estimated by adding the first portions of the test-acid very gradually to the sample, carefully observing the effect. When the effervescence at length commences the weight or measure of the test-liquor expended shows the quantity of pure caustic alkali under treatment (nearly). The result depends upon the fact, that little or no carbonic-acid gas is expelled from the liquid on the addition of the test-acid, until the caustic portion is very nearly neutralised.

The quantity of WATER or MOISTURE, per cent., present in an alkaline carbonate, is indicated by the loss of weight which 100 gr. suffer on gentle ignition in a loosely-covered iron dish or platinum crucible. So also with samples containing caustic alkali, except that here the water of hydration (= 1 equiv. = 9) is not expelled from the ‘caustic’ portion, and must therefore be determined by calculation.

Other matters deserving the serious attention of the operator are—hitting the exact point of neutralisation, and—preparing the test-acids of the proper strength. The method of effecting the former correctly has been already referred to in this article, and is also fully noticed under Acetimetry and Acidimetry.

Test-acids may be very simply prepared by gradually diluting concentrated sulphuric acid with water until it is reduced to the proper strength; the dilution being made in a glass vessel containing a ‘hydrostatic bead’ exactly corresponding to the desired specific gravity of the dilute acid. When the proper point is reached, and the mixture has again acquired the normal temperature of 60° Fahr., the bead rises from the bottom of the vessel, and floats about indifferently in the middle of the liquid. The sp. gr. may then he carefully ascertained by means of an hydrometer or a specific gravity bottle; after which the strength must be accurately determined by means of a standard solution of either pure anhydrous carbonate of soda or pure caustic soda. An acid of any given strength or saturating power may also be prepared in the following manner:—49 parts of commercial sulphuric acid (oil of vitriol), sp. gr. 1·825, contain nearly 40 parts or 1 equiv. of anhydrous sulphuric acid; if we, therefore, wish to prepare a dilute acid containing in every 1000 grains weight, or measure, exactly 1 equiv. of hydrated sulphuric acid, we have only to make 49 gr. of such acid up to 100 gr. weight or measure with pure water. After it has recovered the proper temperature, its sp. gr., or rather its saturating power, must be carefully tried, and, if necessary, readjusted. As, however, it very often happens that the oil of vitriol employed is not so strong as that above referred to, it is better first to test its strength with pure anhydrous carbonate of soda, and to calculate the quantity required by the Rule of Proportion. Every 53 gr. of the dry carbonate are equal to 40 gr. of ‘dry sulphuric acid.’ Suppose we find the oil of vitriol to contain only 72% of hydrated acid, then—

100 : 40 :: 72 : 55·55

or, instead of only 40 gr., fully 55⁄4 gr. will be required, which are to be made up with water to 1000 gr., as before. Finally, the diluted acid must be very carefully re-tested, and if found correct, at once put into a well-stoppered bottle, and labelled, for use. Too much care cannot be taken to ensure the test-liquid, whether for alkalies or acids, being of the proper strength, of which the specific gravity alone is an insufficient proof. In practice, so small a quantity only of test-acid as that referred to above is, of course, seldom made; but as any larger quantities are mere multiples of the smaller one, the necessary proportions to be employed are easily calculated. The common plan is to prepare one or more gallons or quantities of 10 lbs. each, and to preserve the liquid in stoppered green glass ‘Winchester-quart bottles,’ so that it may be always ready for use.

Although, as may be inferred from the text, sulphuric acid is generally used as the standard acid, yet oxalic acid in pure crystals is recommended by M. Mohr, and answers admirably, and is prepared and used exactly in the same manner.

Table II.—Alkalimetrical Equivalents.

Grains. are equivalent to Grains.

22 Carbonic anhydride (dry). 17 Ammonia (pure or gaseous).

63 Oxalic acid (crystallised). 43⁄2 Carbonate of ammonia (neutral, hydrated).

49 Sulphuric acid (liquid, monohydrated, sp. gr. 1·8485). 59 Sesquicarbonate of ammonia (Ph. L.; translucent, hydrated).

75 Tartaric acid (crystallised). 79 Bicarbonate of ammonia (crystallised).

1000 Dilute sulphuric acid (sp. gr. 1·033). 47 Potassa (anhydrous).

56 Hydrate of potassa (pure caustic potassa).

Water—gr. measure. 69 Carbonate of potassa (anhydrous).

1000 Dilute sulphuric acid (sp. gr. 1·032). 83 Carbonate of potassa (granulated, commercial).

87 Carbonate of potassa (crystallised).

100 Bicarbonate of potassa (crystallised).

31 Soda (anhydrous).

40 Hydrate of soda (pure caustic soda).

53 Carbonate of soda (anhydrous).

143 Carbonate of soda (crystallised).

84 Bicarbonate of soda (crystallised).

83⁄2 Sesquicarbonate of soda (average commercial).

84 Bicarbonate of soda (crystals, or cryst. powder, free from moisture).

15 Lithia.

24 Hydrate of lithia.

37 Carbonate of lithia.

76⁄2 Baryta (pure, caustic).

85⁄2 Hydrate of baryta.

98⁄2 Carbonate of baryta.

28 Lime (pure, caustic; i. e. quick-lime).

37 Hydrate of lime (slaked lime).

50 Carbonate of lime (chalk; marble).

20 Magnesia (pure, calcined).

42 Carbonate of magnesia (dry, neutral).

48⁄2 Carbonate of magnesia (ordinary commercial).

52 Stronia (pure, caustic).

61 Hydrate of strontia.

74 Carbonate of strontia.

ALKALOID. Syn. Vegetable Alkali, Organic Base; Alkaloïdes (pl., -IDES, or -IDÆ), L.; Alcaloïde, Alcali organique, Fr. In chemistry, a name commonly given to any proximate principle of vegetable origin possessing alkaline or basic properties, however feeble. In its most extended sense the term embraces all organic bases, whether obtained from the animal or vegetable kingdom, or produced artificially. The alkaloids form a numerous and important class of bodies. They exist in nature nearly always in the form of salts, the acid being often, like themselves, peculiar to the plant, or class of plants, in which they are found; whilst the medicinal activity of the latter, in most cases, almost entirely depends on their presence.

Prep. The following general methods of procuring the alkaloids will be found applicable to such as full directions are not given for under their respective heads:—

1. (When the base is insoluble in water, non-volatile, and existing in the plant in an insoluble form.) The bruised plant is boiled or macerated in water acidulated with hydrochloric or acetic acid, and the liquor, after filtration, is neutralised with an alkali (ammonia, potassa, lime, or magnesia); the resulting precipitate is purified by re-solution in dilute acid, digestion with a little animal charcoal, and subsequent crystallisation, or re-precipitation with an alkali; or the first precipitate is purified by dissolving it once, or, if necessary, several times, in boiling alcohol, which yields the pure alkaloid either on cooling or by evaporation.

2. (When the base is insoluble in water, and non-volatile, but existing in the plant as a soluble salt.) The bruised or sliced plant is boiled or macerated in water, and the filtered liquor precipitated and otherwise treated as before.

3. (When the base is soluble in water, and non-volatile.) An infusion made with very dilute acid, hydrochloric or acetic, is concentrated by a gentle heat; and the residual liquor treated with potassa (or concentrated solution of ammonia) and ether conjointly; after repose, the ethereal solution is decanted and evaporated. For those alkaloids which are insoluble in ether (as morphia and cinchonia), the previous process may be adopted.

4. (When the base is both soluble in water and volatile.) The vegetable, in a bruised or divided state, or its extract, is alkalised with potassa and distilled; the distillate is neutralised with dilute oxalic or sulphuric acid, and carefully evaporated to dryness; the residuum is next digested in alcohol, and the resulting tincture agitated with potassa and ether, the former being in quantity just sufficient to seize on all the acid; lastly, the ethereal solution thus formed, on careful evaporation, leaves the alkaloid nearly pure. It may be further purified by cautious distillation.

As some of the alkaloids are soluble in excess of the alkaline precipitant, over-saturation should be carefully avoided; or the precipitant may be used under the form of carbonate or bicarbonate. When lime and magnesia are employed, they are boiled for a few minutes with the solution.

Props. Alcoholic or aqueous solutions of the alkaloids generally exhibit an alkaline reaction with vegetable colours. Like the alkalies, also, they combine with acids to form salts which, when dissolved in water, are capable of producing the ordinary phenomena of saline double decomposition. Their taste is usually intensely bitter.

The majority of the natural alkaloids contain carbon, hydrogen, nitrogen, and oxygen, and are, at ordinary temperatures, solid, and not volatile without decomposition. Some natural alkaloids contain carbon, hydrogen, and nitrogen only; these are, for the most part, liquid at ordinary temperatures, and can be distilled without decomposition. The greater number of the artificial alkalies are composed of carbon, hydrogen, and nitrogen; some, however, contain oxygen in addition. Alkaloids have also been obtained artificially, in which nitrogen is replaced by phosphorus, arsenic, antimony, or bismuth. Most of the alkaloids, as they are obtained in the free state, correspond in function to ammonia, NH3, rather than to the fixed alkalies; that is to say, they form salts by direct union with acids, without elimination of water or any other substance. In order to make them strictly comparable to the fixed alkalies, they require, like ammonia, the addition of water (H2O) to their formulæ; they may then be considered as hydrates of compound radicles analogous to ammonium.

Physiological action. The alkaloids generally possess great medicinal power; some of them act with terrific energy, and are the most violent poisons with which we are acquainted. Perfectly pure aconitia is about 200 times more poisonous than arsenic, and at least 50 times more poisonous than ordinary medicinal prussic acid. The greater number act on animals in the same way as the plants which produce them, provided they are given in proportionately small doses. Many of them, when judiciously administered, are most valuable medicines.

Pois., Ant., &c. Some of the alkaloids act as narcotic or stupefying poisons; others are classed with the narcotico-acrid poisons, or those which produce both narcotism and irritation of the parts they touch. The general symptoms produced by opium and its preparations may be taken as an example of the former; those from aconite and strychnia, of the latter. In large doses of the greater number, narcotism predominates; in smaller ones, irritation; they are rarely coexistent.—Treatm. No common antidote to the effects of this class of substances has yet been discovered. The only safe treatment, of at all general application, is to immediately clear the stomach by means of a strong and quick-acting emetic (as sulphate of zinc), or the stomach-pump, and to administer copious and continued draughts of astringent vegetable solutions (as of tannin, nut-galls, oak-bark, or what is always at hand—very strong tea or coffee). These may be followed by or combined with a smart purge of castor oil, as soon as the stomach is thoroughly cleared of the poison. M. Bouchardat strongly recommends a solution of iodine, 3 gr., and iodide of potassium, 6 gr., in pure water, 16 fl. oz., in cases of poisoning by OPIUM, ACONITE, COLCHICUM, DEADLY NIGHTSHADE, HEMLOCK, NUX VOMICA, &c., or by the alkaloids obtained from them—ACONITINE, ATROPIA, COLCHICINA, CONIA, MORPHIA, STRYCHNIA, &c., or their salts; but not where foxglove or digitalin has been taken. The stomach having been well emptied by an emetic, the solution is to be given by wine-glassfuls for some time; the vomiting being still encouraged during the early part of the administration of the antidote. In the case of narcotics (as opium, morphia, &c.), this is to be followed by the free use of a strong infusion of coffee. According to Dr Garrod, purified animal charcoal is an ‘excellent antidote’ to many of the alkaloids, including those above enumerated, when taken in poisonous doses; as it not merely absorbs them, but, for the most part, renders them inert. To be serviceable it should be recently prepared and fresh-burnt; and should be given in doses of about an ounce at a time, diffused in warm or tepid water, and frequently repeated. The vomiting which follows its use, owing to the warm water, proves advantageous; but after a sufficient time may be lessened by employing less water, or cooler or even cold water. Drowsiness, if present, may be combated by the subsequent use of strong coffee or tea, as before. We have seen this plan succeed in several cases.—Lesions. These, like the symptoms, vary. In some cases there are redness and inflammation of the stomach and intestines, and turgescence of the vessels of the lungs and brain; in others, these appearances are either slight or wholly wanting. Wherever there has been much cerebral disturbance, traces of congestion are usually discernible.

Detec., Tests, &c. The identification of the pure alkaloids is extremely simple; but their detection, when combined with organic and colouring matters, is a task of considerable difficulty. One or other of the following plans may be adopted for this purpose:—

1. (Merck.) The matter under examination is digested, for several hours, with concentrated acetic acid, added in sufficient quantity to produce a strongly acid reaction; the fluid portion is then strained from the insoluble matter, and the latter being washed with water acidulated with acetic acid, the mixed liquors are gently evaporated to dryness in a water bath; the residuum of the evaporation is boiled first with rectified spirit, and next with rectified spirit acidulated with acetic acid; the mixed liquors are again evaporated, the residuum redissolved or diluted with distilled water, and carbonate of soda or potassa added to feebly alkaline reaction, and the whole, after evaporation to the consistence of a syrup, set aside to repose for 24 hours; it is now again diluted with water, filtered, and the insoluble portion washed with cold distilled water, and digested with concentrated acetic acid; this last solution is diluted with distilled water, and decoloured with pure blood-charcoal (if it be necessary); the fluid, either at once, or after cautious evaporation, may then be tested for the alkaloids, in the usual manner. The charcoal previously used should also be tested in the way described below. This method answers admirably with all the NON-VOLATILE ALKALOIDS, and may be applied to the stomach and viscera, and their contents, and to food, &c., in cases of poisoning.

2. (Stas.) The suspected matter, in a finely divided state, is digested, at 160° to 165° Fahr., with twice or thrice its weight of strong alcohol acidulated (according to the quantity) with ⁄2 dr. to 2 or 3 dr., or more, of pure oxalic or tartaric acid. After a sufficient time, and when the whole has become quite cold, it is thrown on a filter, and the undissolved portion, after being squeezed dry, is washed with strong alcohol. The mixed and filtered alcoholic liquids are then evaporated at a temperature not exceeding 95° Fahr., and, if no insoluble matter separates, the evaporation is continued nearly to dryness; but if fatty or other insoluble matter separates during the process of concentration, the concentrated fluid is passed through a moistened filter, and the filtrate evaporated nearly to dryness, as before. The residuum is next digested with absolute alcohol, in the cold, the insoluble portion, after filtration, washed with alcohol, and the mixed filtrates again evaporated in the air, or in vacuo. The acid residue is now dissolved in a little distilled water, and bicarbonate of soda added as long as effervescence ensues. To this mixture 4 or 5 times its volume of ether is added, and after lengthened agitation (the bottle or tube being held in a cold wet cloth), the whole is allowed to repose for a short time. A little of the supernatant ether is now removed to a small glass capsule or watch-glass, and allowed to evaporate spontaneously. When this leaves oily streaks upon the glass, which gradually collect into a small drop, which emits, when gently heated, a disagreeable, pungent, and stifling odour, the presence of a LIQUID VOLATILE BASE or ALKALOID is inferred; whilst a solid residue or a turbid fluid with small solid particles floating in it, indicates a NON-VOLATILE SOLID BASE. In either case the blue colour of reddened litmus is permanently restored by the residuum. If no residuum is left on the capsule, some solution of pure soda or potassa is added to the liquid, the whole well agitated for several minutes, and the ether (after repose) decanted; an operation which is repeated with fresh ether a second, third, and even a fourth time. The base, or bases (if any are present), will now be found in the mixed ethereal solution, which is, therefore, tested as before. The presence of an alkaloid being detected, the mixed ethereal solutions are allowed to evaporate spontaneously, care being taken, if a volatile alkaloid be present, to neutralise the liquid with an acid before the final evaporation. The last residuum is then tested for the particular alkaloid present, as before.

This method, according to Stas, answers well for all the ALKALOIDS which are soluble in ether; including—ACONITIA, ANILINE, ATROPIA, BRUCIA, CODEIA, COLCHICINA, CONIA, DELPHIA, EMETINA, HYOSCYAMINE, MORPHIA (?), NICOTIA, PETININE, PICOLINE, SOLANINE, STRYCHNIA, VERATRIA, &c. By means of it Stas found nicotia in the heart-blood of a poisoned dog. With such alkaloids as are, however, only very sparingly soluble in ether (as morphia for instance), the result must, necessarily, be doubtful. To detect these, as well as all the alkaloids which are insoluble in ether, it is, therefore, necessary, as directed by Otto, to add to the alkaline fluid left by the decantation of the ether, sufficient solution of soda to dissolve the morphia, &c. (if any has separated), and after the expulsion of the last traces of the ether by a gentle heat, to add a concentrated solution of hydrochlorate of ammonia, and to allow the mixture to repose for some time in the open air. When MORPHIA is present, it separates under the form of small crystals. Or the alkaline liquor may be diluted with distilled water, and treated with charcoal, and this with alcohol, in the manner noticed under method 4 (below).

4. (Graham and Hoffmann—slightly modified.) 2 or 3 oz. of purified animal charcoal are digested in about ⁄2 gal. of the (neutral or only slightly acid) aqueous fluid under examination, with frequent agitation, for 10 to 12 hours, or longer. The liquid is then filtered, and the charcoal left on the filter is washed twice with cold distilled water. The charcoal is then boiled for ⁄2 an hour with about ⁄2 a pint of rectified spirit of 80 or 90%; the ebullition being conducted in a flask having a very long tube, open at both ends, fitted air-tight through the cork, to prevent loss of the alcohol by evaporation. The spirit, which now contains the alkaloid (if any was present in the original liquor), is next filtered whilst hot, and the filtrate is submitted to distillation until the whole of the alcohol is removed. A small quantity (commonly a few drops) of solutions of potassa is then added to the residual aqueous liquor, followed by 1 to 2 fl. oz. of pure ether, after which the whole is well agitated for several minutes, and allowed to repose for a short time. Lastly, the supernatant ether is decanted, and allowed to evaporate spontaneously, when the residuum (if any) left in the capsule may be tested by reagents, as before.

This method was devised for the detection of STRYCHNIA and NUX VOMICA in malt-liquors; but it is equally applicable to the detection of ANY ALKALOID which is soluble in ether. The CHARCOAL TEST may also be employed to detect alkaloids which are insoluble in ether; but then the base must be sought in the aqueous residuum obtained by the evaporation of the alcohol.

The presence of the alkaloids and their salts, in clear solutions, may be thus determined:—

I. (Fresenius).—1. The solution is rendered very slightly alkaline with dilute solution of potassa or soda, added drop by drop:—

a. No precipitate is formed; total absence of the alkaloids. (See 4, below.)

b. A precipitate is formed:—solution of potassa or soda is added, drop by drop, until the liquid exhibits a strong alkaline reaction:—

α. The precipitate redissolves; absence of Brucia, Cinchonia, Narcotina, Quina, Strychnia, and Veratria; probable presence of Morphia.

β. Precipitate does not redissolve, or not completely; probable presence of one or more of the first six of the above-named alkaloids:—the fluid is filtered from the precipitate, mixed with either bicarbonate of soda or of potassa, gently boiled nearly to dryness, and treated with water. If it dissolves completely; absence of morphia; an insoluble residue indicates Morphia.

2. The precipitate 1. b. β. is washed with cold distilled water, dissolved in a slight excess of dilute sulphuric acid, neutralised with a saturated solution of bicarbonate of soda, and allowed to repose a few hours:—

a. No precipitate; absence of Cinchonia, Narcotina, and Quina:—the solution is gently evaporated nearly to dryness, and treated with cold water:—if it dissolves completely, pass on to 4; if there is an insoluble residue, it may contain Brucia, Strychnia, or Veratria. (See 3.)

b. A precipitate:—the filtered fluid is treated as directed at 2 a.; the precipitate is washed with cold distilled water, dissolved in a little hydrochloric acid, ammonia is added in excess, and subsequently a sufficient quantity of ether, agitation being had recourse to:—

α. The precipitate formed by the ammonia redissolves completely in the ether, and the clear fluid separates into two layers; absence of Cinchonia; probable presence of Quina or Narcotina.

β. The precipitate produced by the ammonia does not redissolve in the ether, or not completely; probable presence of Cinchonia, and perhaps also of Quina or Narcotina. The filtered liquid may be tested for these alkaloids as at a.

3. The insoluble residuum after the evaporation of the solution 2. a., or of the filtrate 2. b., is now dried in a water bath, and digested with absolute alcohol:—

a. It dissolves completely; absence of strychnia; probable presence of Brucia, Quina (?), or Veratria:—the alcoholic solution is evaporated to dryness, and, if quina has been already detected, the residue is divided into two portions, one of which is tested for Brucia, the other for Veratria.

b. It does not dissolve, or not completely; probable presence of Strychnia, and perhaps also of Brucia and Veratria:—the filtered fluid is divided into two portions, and tested separately as at a.

4. The original liquid 1. a. may contain Salicine, a proximate vegetable principle closely allied to the alkaloids:—a portion is boiled with hydrochloric acid for some time; the formation of a precipitate shows the presence of Salicin. (See 2, below.)

II. (Larocque and Thibierge.) Terchloride of gold is recommended, by these writers, as a more decisive test for the alkaloids than the ‘double chloride of gold and sodium’ commonly employed for this purpose. The following are the colours of the precipitates which it produces with the aqueous solution of their salts:—Brucia, milk-brown, passing into coffee-brown, and lastly chocolate-brown:—CINCHONIA, sulphur yellow:—MORPHIA, yellow, then bluish, and lastly violet; in this last state the gold is reduced, and the precipitate is insoluble in water, alcohol, the caustic alkalies, and sulphuric, nitric, and hydrochloric acid; it forms with aqua regia a solution which is precipitated by protosulphate of iron:—QUINA, buff-coloured:—STRYCHNIA, canary-yellow:—VERATRIA, pale greenish-yellow. All these precipitates, with the exception mentioned, are very soluble in alcohol, insoluble in ether, and only slightly soluble in water. Those with morphia and brucia are sufficiently marked to prevent these alkalies from being mistaken for each other; and those with brucia and strychnia are, in like manner, easily distinguishable.

III.—Mr Wanklyn discriminates the different alkaloids from the estimation of the ammonia they evolve. His process is as follows:—A small flask with a lateral tube, and connected with a Liebig’s condenser, is charged with about 25 c. c. of an alkaline solution of permanganate potash made by dissolving 200 grammes of caustic potash and 8 grammes of crystallised permanganate of potash in 1 litre of water. A minute quantity of the alkaloid carefully and accurately weighed is now introduced, and the mixture slowly distilled. The most satisfactory results are obtained by treating from 1 to 5 milligrammes of the alkaloid in this way, but quantities so small as ⁄10th of a milligram will in skilled hands give accurate results. The ammonia is formed in the distillate by Nesslerising it, as described under Water analysis. For all practical purposes the poisonous alkaloids may be divided into four classes:

(a) Those which yield from 5 to 2 per cent. of ammonia.

(b) Those which yield from 2 to 3 per cent. of ammonia.

(c) Those which yield from 3 to 5 per cent. of ammonia.

(d) Those which yield a larger quantity than 5 per cent., e.g.

I.

NH3 per cent.

Solanine yields half its nitrogen as Ammonia 0·98

II.

Morphia yields half its nitrogen as Ammonia 2·98

Codeine, ditto, ditto 2·87

Papaverine, ditto, ditto 2·50

Veratria, ditto, ditto 2·87

III.

Atropia yields all its nitrogen as Ammonia 5·73

Narcotine, ditto, ditto 4·11

Strychnia yields half its nitrogen as Ammonia 5·09

Brucine, ditto, ditto 4·32

Aconite, ditto, ditto 3·50

Coneine, ditto, ditto 4·60

IV.

Nicotine yields half its nitrogen as Ammonia 10·49

IV. Dr Guy, as well as others, have made researches, having for their object the determination of the exact temperature at which the poisonous alkaloids melt and sublime. A very minute speck of the substance is placed on a porcelain plate or copper disc, and a square or oval of microscope-covering glass is placed over it, supported by a thin ring of glass or any other convenient substance.

Heat is then applied to the plate or copper, and the temperature, as indicated by a thermometer at which the substance fuses or volatilises, is carefully noted.

Fahr. Cent.

Cantharidine sublimes as a white vapour without change of form or colour. 212° 100°

Sublime. Melt.

Fahr. Cent. Fahr. Cent.

Morphine Sublime, melt and yield carbonaceous residue. 330° 165° 340° 171°

Strychnine 345° 174° 430° 224°

Melt. Sublime.

Fahr. Cent. Fahr. Cent.

Aconitine Melt, change colour, sublime, and deposit carbon. 140° 60° 400° 204°

Atropine 150° 66° 280° 138°

Veratrine 200° 93° 360° 182°

Brucine 240° 116° 400° 204°

Digitalin 310° 154° 310° 154°

Picrotoxin 320° 160° 320° 160°

Solanine 420° 215° 420° 216°

Selmi’s method of extracting poisonous alkaloids in forensic investigations. The alcoholic extract of the viscera, acidified and filtered, is evaporated at 65° C., the residue taken up with water, filtered to separate fatty matters, and decoloured by means of basic acetate of lead, leaving the solution in contact with the air for 24 hours. It is then filtered, the lead precipitated by means of sulphuretted hydrogen, and the solution after concentration repeatedly extracted with ether. The ethereal solution is then saturated with dry carbonic anhydride, which generally causes a precipitate of minute drops adhering to the sides of the vessel, and containing some of the alkaloids. The ethereal solution is then poured into a clean vessel, mixed with about half its volume of water, and a current of carbonic anhydride passed for about twenty minutes, which may cause the precipitation of other alkaloids not precipitated by dry carbonic anhydride. Usually the whole of the alkaloids present in the ether are thrown down by these means, but if not, the solution is dehydrated by agitation with Barium oxide, and then a solution of tartaric acid in ether added to the clear liquid, taking great care not to employ excess of acid. This throws down any alkaloid that may remain. In order to extract any alkaloids that may still remain in the viscera, they are mixed with Barium hydrate and a little water, and then agitated with purified amylic alcohol; the alkaloids may subsequently be extracted from the alcohol by agitation with very dilute sulphuric acid.

A knowledge of the different solubilities of the alkaloids will be found an important auxiliary in their analysis. The following is a summary of the relative solubility of the most important of them. The figures denote the number of parts of the liquid required for their solution:—

Absolute alcohol.—Strychnine insoluble; brucine soluble.

Amylic alcohol.—Solanine (1061); digitalin sparingly soluble; morphine (133); strychnine (122); veratrine, brucine, atropine, aconitine, and picrotoxin, freely soluble.

Benzol.—All the poisonous alkaloids, except solanine, are soluble in benzol.

Chloroform.—Solanine (50,000); morphine (6550); strychnine (8); the rest freely soluble.

Ether.—Solanine (9000); morphine (7725); strychnine (1400); aconitine (777); brucine (440); veratrine (108); atropine, picrotoxin, and digitalin, very soluble.

Water (cold).—Strychnine (8333); veratrine (7860); morphine (4166); aconitine (1783); solanine (1750); brucine (900); atropine (414); picrotoxin (150); digitalin very soluble.

The principal Alkaloids and their Salts, in the state of powder, or with ‘conia’ and ‘nicotia,’ in the state of an oily looking liquid, may be thus distinguished:—

1. a. The powder is treated with nitric acid:—It is coloured red; probable presence of Brucia, Delphia, Morphia, or commercial Strychnia. If the reddened acid becomes violet on the addition of ‘protochloride of tin,’ it is Brucia; if it becomes black and carbonaceous, it is Delphia. If the powder is fusible without decomposition, and strongly decomposes iodic acid, it is Morphia; if it is not fusible without decomposition, and does not decompose iodic acid, it is Strychnia.

b. If instead of a red, the powder strikes a green colour with nitric acid, it is Solania; if it is insoluble in ‘ether,’ and not reddened by ‘nitric acid,’ it is Emetia; if soluble in ether, not reddened by ‘nitric acid,’ but melts and volatilises when heated, it is Atropia; if it is thus affected by ether or nitric acid, but does not volatilise, it is Veratria. (See 2, below.)

2. a. The powder, or (with ‘conia and nicotia’) concentrated liquor, is treated with a drop or two of concentrated sulphuric acid:—A red colour is produced; probable presence of Brucia, Nicotina, Salicine, or Veratria. If the reddened mixture has at first a roseate hue, turning deep red on the addition of nitric acid, it is Brucia; if the original substance moistened with solution of potassa evolves the odour of tobacco, it contains Nicotine; if the red colour produced by the acid is permanent and of an intense blood-hue, and the powder agglutinates into lumps like resin, it is Salicine; if the colour is at first yellowish, changing to blood-red, and ultimately to crimson and violet, it is Veratria.

b. If instead of the substance being ‘reddened’ by strong sulphuric acid, no particular action ensues in the cold, it contains either Conia or Strychnia; if a small fragment of bichromate of potassa being now dropped in, produces a rich violet colour, it is Strychnia; if the original matter on being heated, or treated with solution of potassa, evolves a penetrating, disagreeable odour, somewhat analogous to that from ‘hemlock,’ or to a mixture of those from tobacco and mice, it is Conia.

“Reactions with ceroso-ceric oxide. This oxide exhibits characteristic colours with several alkaloids, especially with STRYCHNINE. When strong sulphuric acid is poured upon strychnine, and then a small quantity of ceroso-ceric oxide added, a fine blue colour is produced, similar to that which strychnine exhibits with potassium bichromate, but much more permanent. The blue colour gradually changes to cherry-red, and then remains unaltered for several days. This reaction is capable of detecting one part of strychnine in a million parts of liquid. Brucine similarly treated acquires an orange-colour, gradually changing to yellow; MORPHINE, olive-brown, finally brown; NARCOTINE, brown cherry red, finally wine-red; CODEINE, olive-green, finally brown; QUININE, pale-yellow; CINCHONINE and THEINE remain colourless; VERATRINE becomes reddish-brown; ATROPINE, dingy yellowish-brown; SOLANINE, yellow at first, finally brownish; EMETINE, brown; COLCHICINE, first green, then dirty brown; ANILINE, after a long time, acquires a blue colour extending from the edges inwards; CONINE becomes light-yellow. Piperine colours the sulphuric acid blood-red, and is turned dark-brown, almost black by the cerium oxide” (Sonnenschein).

“Reactions with picric acid. This acid is a very good precipitant for alkaloids, affording a very delicate test for many of them, and may perhaps also serve for separating them one from another. The precipitation takes place even in solutions containing a large excess of sulphuric acid, and is sometimes complete. Precipitated are, BRUCINE, STRYCHNINE, VERATRINE, QUINIDINE, CINCHONINE, and most of the opium alkaloids; not precipitated, MORPHINE, ATROPINE (English), PSEUDO-MORPHINE, CAFFEINE, and all glucosides” (Hager).

The presence of one or more of the alkaloids being shown by any of the preceding methods, a portion of the original clear solution or powder, or of the precipitates or filtrates above referred to, must be treated with their characteristic tests, as given under the individual notices of these articles, so as to set at rest all doubt as to their identity. No single test must ever be relied on as a positive proof. The presence of Brucia, Morphia and Strychnia may be determined in substances which after being mixed with the salts of these alkaloids have undergone the acetous, vinous, or putrefactive fermentation, as shown by Orfila, MM. Larocque and Thibierge, and many other eminent chemists and toxicologists, and confirmed, in numerous cases, by our own experiments. Opium and morphia may thus be readily detected in beer, wine, soup, and milk. A paper by Professor Dragendorf in the ‘American Chemist’ for April, 1876, may be consulted with advantage.

Concluding Remarks. It is a singular fact that none of the organic bases found in plants have yet been formed artificially, although several analogous substances have been thus produced. Closely allied to the alkaloids there also exists an extensive series of neutral proximate principles, which differ from those substances chiefly in the absence of basic properties, and in most of them being destitute of nitrogen. They are usually bitter, and, like the alkaloids, generally represent the active properties of the plants in which they are found; whilst some of them possess considerable medicinal energy. Of this kind are asparagin, elaterin, gentianin, picrotoxin, salicin, &c. These two classes of bodies, though actually distinct, are frequently confounded. See Alkali, Organic Bases, Poisons, Proximate Principles, Vegetables, Nomenclature, &c.; also the individual alkaloids under their respective heads.

ALKALOIDS OF ACONITE. The nature of the active principle of aconite root does not appear to have been satisfactorily determined. Messrs Groves, Wright, and Williams contend that the Aconitum napellus yields an active crystalline alkaloid, which they distinguish as Aconitine, and to which they assign the formula C33H43NO12; they add that additionally the root contains more or less of another active alkaloid, which they term Pseudaconitine, and which is represented by the formula C36H49NO11; they also assert that the extract of the roots contains varying quantities of certain decomposition products resulting from the saponification of the above bases by the acids, which are produced by the breaking up of part of the aconitine. The name of these decomposition products is Aconine and Pseudaconine. Of Aconitum ferox they report that it yields a comparatively large quantity of Pseudaconitine and a small quantity of Aconitine. They further affirm that the so-called aconitine of commerce is a mixture of true aconitine and pseudaconitine with variable quantities of their alteration products, aconine and pseudaconine, and of certain amorphous unnamed alkaloids.

Messrs Paul and Kingzett contest the accuracy of these deductions, and dispute the correctness of the formula given to aconitine. Dr Paul doubts whether the alkaloid to which the active properties of the root are ascribed has ever yet been obtained in an isolated condition. He thinks it probable that the substance obtained from aconite root was to a great extent a salt of an acid, like aconitic acid. For further information the reader is referred to the ‘Pharmaceutical Year Book’ for 1873, 1874, 1875, 1876, and 1877.

AL′KANET. Syn. Anchu′sa, L.; Orcanette, Fr.; Orkanet, Ger.; Or′chanet*, Dyer’s al′kanet, D. bu′gloss*. The anchu′sa tincto′′ria (Willd.; lithosper′mum tincto′′rium—Linn.), a deciduous herbaceous plant, with a perennial, dark blood-red root. Hab. Asia Minor, Greece, Hungary, &c. It is also largely cultivated in the neighbourhood of Montpellier. The dried root (ALKANET ROOT; RADIX ANCHUSÆ, R. A. TINCTORIÆ) is chiefly imported from the Levant. It contains a beautiful blood-red colour, which it freely gives out to oils, fats, wax, spirits, essences, and similar substances, by simply infusing it in them, and is consequently much employed to colour these articles. Wax tinged with it, and applied on warm marble, stains it of a rich flesh-colour, which sinks deep into the stone, and possesses considerable durability. Its spirituous tincture also imparts a deep red to marble.

Prop., &c. The colouring matter of alkanet was regarded by Pelletier as a fatty acid (ANCHUSIC ACID); but it has since been shown to be a species of resin (ANCHUSINE, PSEUDO-ALKANNINE, P.-ALKANIUM). According to Dr John, good alkanet root contains 5⁄2 per cent. of this substance. Anchusine melts at 140° Fahr.; is scarcely soluble in water, to which it only imparts a dirty red colour, but is very soluble in alcohol, oils, and acetic acid. Alkalies turn it blue. It is found wholly in the root-bark. In selecting this article, the smaller roots should therefore be chosen, as they possess more bark than the larger ones, in proportion to their weight. Exposure to ammoniacal fumes, or even handling it much with the fingers, changes its red to a crimson or purplish hue.

Uses, &c. It is much employed by druggists and perfumers to colour oils, lip-salves, plasters, pomatums, &c.; by varnish-makers, to tinge their varnishes and lacquers; by statuaries to stain marble; by dairy-farmers, to colour cheese; by wine-merchants and bottlers (in the form of tincture), to stain beforehand the corks of their port-wine bottles, in order to imitate the effects of age, and as colouring and flavouring for factitious port wine; and by dyers, and others. A species of crimson rouge was formerly prepared from it (hence its name).

ALLANTO′IC ACID. See Allantoin.

ALLAN′TOIN. C8H6O6N4. Syn. Allanto′ic acid*, Amniot′ic a.† Am′nic a.†; Allantoï′na, L. A substance discovered by Vauquelin and Buniva in what they imagined to be the liquor amnii of the cow, and hence named by them amniotic acid. It was afterwards shown by Dzondi and Lassaigne to exist in the fluid of the allantoïs, and not of the amnios. It has since been produced artificially by Wöhler and Liebig.

Prep. 1. The allantoïc fluid of the fœtal calf is evaporated to 1-4th or 1-5th of its volume, and then set aside for some time. The crystals thus obtained are purified by re-solution, digestion with animal charcoal, and re-crystallisation.

2. (Wöhler and Liebig.) Uric acid, 1 part; is dissolved in water, 20 parts; and freshly precipitated and well-washed binoxide of lead is added to the solution until the colour ceases to change; the liquid is next filtered while hot, evaporated until a pellicle forms on the surface, and then set aside to crystallise; the crystals being purified as before.

Prop., &c. Small, but very brilliant prismatic, transparent, colourless crystals; tasteless; neutral; soluble in 160 parts of cold water, and in much less at 212°; nitric acid converts it into ALLANTURIC ACID; oil of vitriol resolves it into ammonia, carbonic acid, and carbonic oxide; hot concentrated solutions of the caustic alkalies change it into ammonia and oxalic acid.

ALLANTOX′ICUM. [L.] Syn. Allantox′icum, L. (prim., Gr.). The poison developed, during putrefaction, in sausages made of blood, liver, &c. “It often proves speedily fatal.” (Kraus.)

ALLGEMEINE FLUSSTINCTUR (Sulzberger, Salzungen). For the relief of a number of diseases, among which are cholera and sea-sickness. Aloes, 1 part; spirit of wine, 2 parts. (Spau.)

ALLIA′CEOUS (-sh′us). Syn. Allia′ceus, L.; Alliacé, Ailiacé, Fr.; Knoblauchartig, &c., Ger. Garlick-like; an epithet applied to substances having the odour or properties of garlic or onions.

Alliaceous Plants. Chives, garlic, leeks, onions, rocambole, shallots, &c.

ALLIGA′TION. Syn. Alliga′tio, L. In commercial arithmetic, a rule for ascertaining the price or value of mixtures, and for determining the proportions of the ingredients that must be taken to produce mixtures of any given price, value, or strength. The first is called ALLIGATION ME′DIAL; the second, ALLIGATION ALTERN′ATE. Its principles and applications are explained under Mixtures (Arithmetic of).

ALLOP′ATHY. Syn. Allopa′thia, L. (from ἁλλος, other, different, and παθος, affection or disease, Gr.); Allopathie, Fr. In medicine, the method of curing disease by the use of remedies which tend to produce a condition of the system, either differing from, opposed to, or incompatible with the condition believed to be essential to the disease it is sought to cure. It is commonly employed to distinguish the ordinary system of medical practice from homœopathy (which see). Hence (an) ALLOP′ATHIST, and the corresponding adjective ALLOPATH′IC (allopath′icus, L.).

ALLOT′ROPY. Syn. Allot′ropism; Allotro′pia, Allotropis′mus, L. Literally, a difference in character; another form of the same substance. In chemistry, a term invented, by Berzelius, to express the state or condition, or the change of character, assumed by certain substances at different temperatures, or under different treatment, whilst their nature and composition continue the same. It more particularly relates to colour, hardness, solubility, texture, &c. Boron, carbon, silicon, iron, sulphur, and phosphorus, afford striking examples of the changes here referred to.

ALLOX′ANTIN. C8H4N4O7.3H2O. A crystallisable substance, first obtained by Dr Prout from uric acid.

Prep. 1. Uric acid, 1 part; is boiled in water, 32 parts; dilute nitric acid being added until solution is complete; the resulting liquid is evaporated to ⁄3rds its volume, and then set aside for 10 or 12 hours; the crystals, which are deposited, are purified by re-solution and crystallisation.

2. Sulphuretted hydrogen gas is passed, in a full stream, through a moderately strong aqueous solution of alloxan, in the cold. The alloxantin, which is deposited as a crystalline mass, is purified by draining, cautious washing with cold water, re-solution in boiling water, and re-crystallisation. The impure mother-liquor from which crystals of alloxan have separated, if diluted with water, may be used for this purpose.

Prop., &c. Crystals, small colourless, transparent, four-sided, oblique rhombic prisms; scarcely soluble in cold water; solution reddens litmus; with baryta water it gives a characteristic violet-coloured precipitate, which disappears on heating; and with nitrate of silver a black precipitate of that metal; the crystals are reddened by ammoniacal vapours.

ALLOY′. Syn. Alliage, Fr.; Legirung, Vermischung durch schmelzen, Ger. In coinage, a compound of the precious metals with another, or others, of less value; also the least valuable metal, or metals, in such compounds. In chemistry and metallurgy, combinations of the metals with each other usually obtained by fusion. When mercury is one of the component metals, the compound is termed an AMALGAM.

Prep., &c. No General rules can be given for this purpose. Alloys of metals differing greatly in fusibility, are commonly made by adding the more fusible one, either in the melted state, or in small portions at a time, to the other melted, or heated to the lowest possible temperature at which a perfect union will take place between them. The mixture is usually affected under a flux, or some material that will promote liquefaction, and prevent volatilisation and unnecessary exposure to the air. Thus, in melting lead and tin together, for solder, resin, or tallow is thrown upon the surface; in tinning copper, the surface is rubbed with sal ammoniac; and in combining some metals, powdered charcoal is used for the same purpose. Quicksilver combines with many metals in the cold, forming AMALGAMS.

Comp. The following Table exhibits the composition of the more important compounds of this class:—

Table of the principal Alloys.

Names. Combining metals.

Albata See German Silver.

Amalgams Mercury and other metals.

Bath-metal Copper and zinc.

Bell-metal Copper and tin.

Brass Copper and zinc.

Britannia metal Tin with antimony, copper, and bismuth.

Bronze Tin and copper.

Bronze aluminium Copper and aluminium.

Cannon-metal Tin and copper.

Dutch gold Copper and zinc.

Fusible metal Bismuth, lead, and tin.

German silver Copper, nickel, and zinc, with, sometimes, a little iron and tin.

Gold (standard) Gold with copper.

Gold (old standard) Gold with copper and silver.

Gun-metal See Cannon-metal.

Mosaic gold Copper and zinc.

Or-molu Copper and zinc.

Pewter (common) Tin and lead.

Pewter (best) Tin with antimony, bismuth and copper.

Pot-metal, Cock-metal Copper and lead, with, sometimes, a little zinc.

Queen’s metal Tin with antimony, bismuth, and copper.

Shot-metal Lead with a little arsenic.

Silver (standard) Silver and copper.

Solder Tin and lead.

Speculum-metal Tin and copper, and arsenic.

Stereotype-metal Lead, antimony, and bismuth.

Tombac, Red Tombac Copper and zinc.

Tutania See Britannia metal.

Type-metal Lead and antimony.

White copper (Packfong; Whitetombac) Copper and arsenic.

Prop., &c. Alloys generally possess characteristics unshared by their component metals. Thus, copper and zinc form brass, which has a different density, hardness, and colour to either of its constituents. Whether the metals tend to unite in atomic proportions, or in any definite ratio, is still undetermined. The evidence afforded by the natural alloys of gold and silver, and by the phenomena accompanying the cooling of several alloys from the state of fusion, goes far to prove that such is the case. (Rudberg.) The subject is, however, one of considerable difficulty, as metals and metallic compounds are generally soluble in each other, and unite by a simple fusion and contact. That they do not combine indifferently with each other, but exercise a species of elective affinity not dissimilar to other bodies, is clearly shown by the homogeneity and superior quality of many alloys in which the constituent metals are in atomic proportions. The variation of the specific gravity and melting-points of alloys from the mean of those of their component metals, also affords strong evidence of a chemical change having taken place. Thus, alloys generally melt at lower temperatures than those required for their separate metals. They also usually possess more tenacity and hardness than the mean of their constituents.

Matthiessen found that when weights are suspend to spirals of hard-drawn wire made of copper, silver, gold, or platinum, they become nearly straightened when stretched by a moderate weight; but wires of equal dimensions composed of copper-tin (12% of tin), silver-platinum (36% of platinum), and gold-copper (84% of copper), scarcely undergo any permanent change in form when subjected to tension by the same weight.

The same chemist gives the following approximative results upon the tenacity of certain metals and wires hard drawn through the same gauge (No. 23):

Breaking strain for:

lbs.

Copper 25-30

Tin under 7

Lead ” 7

Tin-lead (20% lead) about 7

Tin-copper (12% copper) ” 7

Copper-tin (12% tin) ” 80-90

Gold 20-25

Gold-copper (8·4% copper) 70-75

Silver 45-50

Platinum 45-50

Silver-platinum (30% platinum) 75-80

On the other hand, their malleability, ductility, and power of resisting oxygen is generally diminished. The alloy formed of two brittle metals is always brittle; that of a brittle and a ductile metal, generally so; and even two ductile metals sometimes unite to form a brittle compound. The alloys formed of metals having different fusing-points are usually malleable whilst cold, and brittle whilst hot. The action of the air on alloys is generally less than on their simple metals, unless the former are heated. A mixture of 1 part of tin and 3 parts of lead is scarcely acted on at common temperatures; but at a red heat it readily takes fire, and continues to burn for some time like a piece of bad turf. In like manner, a mixture of tin and zinc, when strongly heated, decomposes both moist air and steam with almost fearful rapidity.

The specific gravity of alloys is never the arithmetical mean of that of their constituents, as commonly taught; and in many cases considerable condensation or expansion occurs. When there is a strong affinity between two metals, the density of their alloy is generally greater than the calculated mean; and vice versâ, as may be seen in the following Table:—

Alloys having a density—

Greater than the mean of their constituents:— Less than the mean of their constituents:—

Copper and bismuth, Gold and copper,

” palladium, ” iridium,

” tin, ” iron,

” zinc, ” lead,

Gold and antimony, ” nickel,

” bismuth, ” silver,

” cobalt, Iron and antimony,

” tin, ” bismuth,

” zinc, ” lead,

Lead and antimony, Nickel and arsenic,

Palladium and bismuth, Silver and copper,

Platinum and molybdenum, Tin and antimony,

Silver and antimony, ” lead,

” bismuth, ” palladium,

” lead, Zinc and antimony.

” tin,

” zinc.

“Every alloy,” says Dr Ure, “is, in reference to the arts and manufactures, a new metal, on account of its chemical and physical properties. A vast field here remains to be explored. Not above sixty alloys have been studied by chemists, out of many hundreds which may be made, and of these very few have yet been practically employed. Very slight modifications often constitute very valuable improvements upon metallic bodies.” See Analysis, Assaying, Brass, Bronze, Electrotype, German Silver, Gold, Metals, Specific Gravity, &c.

ALL′SPICE. See Pimento.

ALLU′′VIAL. (-l’ōōv′-yăl). Syn. Allu′′vious*; Allu′′vius, L.; d′Alluvion, Fr. In geology, applied to partial deposits of mud, sand, gravel, &c., left by rivers and floods upon land not permanently submerged beneath water; in agriculture, applied to soils so formed or deposited.

ALLU′′VIUM. [L., Eng.] Syn. Alluvion, Fr.; Anflössung, Anschwemmung, Ger. In geol. and agr., alluvial deposit or soil. See Soils, &c.

AL′LYL (-lĭl). C3H5. In chemistry, the radical of the essential oils containing sulphur, as those of assafœtida, garlic, horseradish, mustard, onions, &c., which are either sulphides or sulphocyanides of allyl. Its probable existence was first shown by Captain Reynolds, who succeeded in producing several of its derivatives. It has since been obtained, in a separate state, by the action of sodium upon iodide of allyl. It is an oily substance with a high boiling point.

Allyl, Sulphide of, (C3H5)2S; obtained (artificially) by acting on sulphocyanide of allyl with sulphide of potassium. See Oil of Garlick.

Allyl, Sulphocy′anide of, C3H5CNS; obtained by submitting iodide of allyl to the action of sulphocyanide of potassium; or by gently heating a mixed alcoholic solution of sulphide of allyl and bichloride of mercury, with sulphocyanide of potassium. See Oil of Mustard (Volatile).

AL′MOND (ah′-mŭnd). Syn. Amyg′dala (also -US, -UM*), L.; Amande, Fr.; Mandel, Ger., Dut., Dan., Swed. The ‘almond-tree’ (amyg′dalus commu′nis—Linn.; Ph. L., E., and D.; Amandier—Fr.), a tree of the nat. ord. Rosaceæ, indigenous to Persia, Syria, and the north of Africa; but also extensively cultivated in southern Europe. The almond-tree is about the size of the peach-tree, which it much resembles in appearance. It is incapable of ripening its fruit in this country, and is, therefore, only grown here for the sake of its beautiful vernal flowers. There are several varieties, of which the most important are the sweet and the bitter, so named from the flavour of the seed or kernel. These, for the most part, resemble each other in appearance. De Candolle (‘Prodromus,’ ii, 530) gives five varieties of this species:—A. AMA′′RA (bitter-almond); A. DUL′CIS (sweet-a.); A. FRAGILIS (tender-shelled a.); A. MACROCAR′PA (large-fruited a., pista′chio a., sultana a.); A. PERSICO′ÏDES (peach a.).

Almond, Per′sian. The peach.

AL′MONDS. Syn. Amyg′dalæ, L.; Amandes, Fr.; Mandeln, Ger. The seed or kernels of the almond-tree. They are met with in commerce both in the shell (AMYG′DALÆ CUM PUTAM′INE, -ĭn-e, L.), and shelled (AMYGDALÆ, L.). In the retail shops, most commonly in the latter form. Those rancid, broken, or worm-eaten should be rejected.

Almonds, Bitt′er. Syn. Amyg′dalæ ama′′ræ, L.; Amygdala amara, Ph. E.; Amandes Amères, Fr.; Bittere mandeln, Ger. A variety imported from Mogadore, chiefly characterised by possessing the bitter flavour, and when rubbed with water, the odour of peach-kernels. They are also smaller and thicker than the sweet almond.

Uses, &c. Bitter almonds are used to relieve the flavour of sweet almonds, to clear muddy water, and to flavour confectionery, liqueurs, &c. By pressure, they yield their bland oil (OIL OF ALMONDS; O′LEUM AMYG′DALÆ, L.); the resulting cake (BITTER-A. CAKE; PLACEN′TA A. AMARÆ, L.) is distilled for the volatile oil (ESSENTIAL OIL OF A.; O. A. A., L.), and is afterwards again pressed into cakes (A.-CAKE), and used to fatten pigs, and for other purposes. Bitter almonds are now seldom employed in medicines, although it is said that they have cured ‘intermittents’ when bark had failed (Bergius), and that their emulsion has been found useful in pulmonary and dyspeptic affections, hooping-cough, and asthma; and externally as a lotion in acne. (Thomson.) In large quantities they are poisonous, and even in the smallest quantities have been known to produce nettle-rash (urticaria) and other unpleasant symptoms. They have long been in repute as an antidote to intoxication. The ancient bacchanals chewed them at their orgies, to lessen the effects of wine, and to enable them to take it in larger quantities with impunity.

Almonds, Blanched′ (blăncht′-). Syn. Amyg′dalæ decortica′tæ, L. Almonds from which the husk or seed-coat has been removed. This is effected by soaking them for a short time in warm water, until the skin can be easily removed by pressure between the thumb and forefinger. They are then peeled, rinsed in cold water, drained, and dried. When intended for the table, the last is effected by wiping them with a soft towel; but when they are intended to be powdered, or kept, they are dried by a very gentle heat in a stove, or in the sun.

Almonds, Burnt′. Syn. Roasted almonds; Almond coffee. Used to colour and flavour liqueurs and confectionery; and formerly, as a substitute for coffee.

Almonds, Guia′na. (ghe-āh′-nă; g hard). Brazil-nuts.

Al′monds, In′dian. The fruit of terminalia catappa (Linn.). They are oleaginous, and nutritious; and are used as a substitute for almonds.

Almonds, Ja′va (jāh′-). The nuts or kernels of canarium commune (Linn.). They are eaten, made into bread, and pressed for their oil.

Almonds, Sweet′. Syn. Almonds; Amyg′dalæ, L.; A. dulces, Ph. D.; Amygdala, A. Jordan′ica, Ph. L.; A. Dulcis, Ph. E., & Ph. L. 1836; Amandes, Amandes douces, Fr.; Süsse mandeln, Ger. These are the well-known dessert or table fruit of the name, and are the kind always referred to when ‘almonds’ (simply) are spoken of or ordered.

Comm. var.—1. Jor′dan Almonds, which are the finest, and are imported from Malaga. Of these there are two kinds; the one, above an inch in length, flat, and with a clear brown cuticle, sweet, mucilaginous, and rather tough; the other, more plump, and pointed at one end, brittle, but equally sweet with the former.—2. Valen′tia a. (which come next in quality) are about ⁄8ths of an inch broad, not quite an inch long, round at one end, and obtusely pointed at the other, flat, of a dingy brown colour, with a dusty cuticle.—3. Bar′bary and Ital′ian a., which resemble the latter, but are generally smaller and less flattened.—4. A variety, of medium quality, imported in baskets from Spain.

Uses, &c. Sweet almonds are nutritive, emollient, and demulcent; but frequently disagree with weak stomachs. The husk is apt to occasion indigestion and nausea. Owing to a peculiar idiosyncrasy of some habits, dyspepsia, diarrhœa, œdematous swelling of the face, and urticaria (nettle-rash), sometimes, though seldom, follow the use of unblanched almonds. Blanched almonds do not produce these inconveniences, and, therefore, should be preferred for the table. In medicine, almonds are employed chiefly under the form of emulsion, confection, &c., and to suspend oily substances in water. Their uses for dietetical purposes are well known. Preparations of them are also employed as cosmetics. The cake left after expressing the oil (ALMOND-CAKE) is used for washing the skin, which it is said to render beautifully soft and clear. See Almond Paste, &c.

AL′NIGHT† (awl′-). A cake of wax with a wick in the midst. The forerunner of, and a rude form of the modern dumpy night-lights called MORTARS.

AL′OE (ăl′-o). Syn. Al′oë (-o-ē), L., Fr. (or ALOÈS), Ger., Ital., Sp., Belg., Dan., Dut., Swed. The aloe-tree. In botany, a genus of plants of the nat. ord. Liliaceæ (DC). The species, of which there are several, are succulent plants or small trees with endogenous stems, and stiff, fleshy, hard, pointed leaves, abounding in a purgative principle (ALOES), which is obtained from them by either evaporating the expressed juice or the decoction. They are all natives of warm climates, and most of them are indigenous to southern Africa.

Hist. , aehleem (aloe-trees), were known to the sacred historians; and both the plant and the inspissated juice are described by Dioscorides and Pliny.

Uses, &c. In Africa, the leaves of the Guinea aloe are made into ropes, fishing-lines, bow-strings, stockings, hammocks, &c. The leaves of another species are used to catch and hold rain-water. The expressed juice and decoction are also used by the natives as a distaff. (Vide infrà.) Comparative trials, made in Paris, of the strength of cordage and cables formed of hemp, and of the aloe from Algiers, are said to have shown the great superiority of the latter. Fabroni obtained a fine violet colour from the recent juice of the aloe, which has been proposed as a dye for silk.

American Aloe. The agave Americana (Linn.) is a plant unconnected with the preceding, and belonging to the nat. ord. Bromeliaceæ. It is found in all parts of tropical America, and is largely cultivated on the shores of the Mediterranean; and less frequently, as an exotic plant in this country. It grows to the height of about 20 feet, and takes many years to produce its gigantic and magnificent pyramid of flowers; shortly after which it perishes, exhausted, as it were, by its efforts in bestowing its rare beauty on the floral world. The vulgar belief is that it blossoms only once in a century; but, as stated by the late Mr Loudon, it flowers sooner or later according to the culture bestowed on it. Its sap yields a kind of honey (AGAVE HONEY), and by fermentation an intoxicating liquor (PULQUE); desiccated juice, mixed with wood ashes, is used as soap, and lathers either with sea or fresh water; leaf-fibre, used as hemp to make thread and twine.

AL′OE-RESIN. Syn. Resi′na Al′oës, L. The resinous matter deposited by a decoction of aloes as it cools.

Prep. (Ph. L. 1746.) Boil aloes, 1 part, in water, 8 parts, and allow the decoction, strained whilst hot, to repose until the next day; then wash the deposited RESIN, and dry it by a gentle heat. It is probably a mixture of aloine and oxidised extractive.

AL′OES (-ōze). Syn. Bitt′er Aloes‡; Al′oë (-o-ē), L.; Aloès, Suc d’Aloès, Fr.; Aloe, Glausinde Aloe, Ger. The inspissated juice or extract of several species of aloe.

Comp., Prep., &c. Aloes is a complex resinous substance containing a body called aloin, which is its active or purgative principle. It is completely soluble in boiling water, and in alcohol or rectified spirit. The decoction deposits an impure resin or resinoid on cooling.

Phys. eff., Uses, &c. Aloes is a warm stimulating purgative, in doses of 3 to 10 gr.; whilst even 1 or 2 gr. seldom fail to produce one motion without pain or inconvenience. It is considered highly serviceable in hypochondriacal, hysterical, and dyspeptic affections, particularly in phlegmatic habits, and in cases arising from deficiency of bile. As an emmenagogue, and a vermifuge, few medicines are more valuable. It acts on the large intestines, and principally on the rectum; and, therefore, should be administered with caution, or only in small doses, where there is a tendency to prolapsus or piles, and in cases where uterine stimulants (as in pregnancy, &c.) would be improper. “It is remarkable with regard to it, that it operates almost to as good a purpose in a small as in a large dose; and one or two grains will produce one considerable dejection, and twenty grains will do no more, except it be that in the last dose (case) the operation will be attended with griping, &c. It is one of the best cures for habitual costiveness.” (Cullen.) Many of the effects complained of arise from its slow solubility in the primæ viæ, and may be obviated by administering it in a liquid form, or in a solid form combined with soap, which renders it freely soluble in the juices of the stomach.

Aloes is more frequently taken than, perhaps, any known purgative. It enters into the composition of a majority of the aperient medicines prescribed by the faculty, and forms the principal ingredient of nearly all the advertised purgative, antibilious, and universal pills of the nostrum-mongers. The fact of aloetic pills not acting until about 8 to 10 hours after being swallowed—so that if taken on retiring to rest at night they do not generally disturb the patient before the usual time of rising in the morning—has contributed more than anything else to make such remedies popular with parties whose habits or business avocations would be otherwise interfered with.

Aloes is also extensively used in veterinary practice. It is the most valuable and reliable purgative for the horse of the whole materia medica; but is less to be depended on for cattle, sheep, and hogs. Barbadoes aloes is the best for this purpose. Cape aloes are, however, often employed, when 1-4th more must be given.—Dose (of the former), for a HORSE, 4 to 8 dr.;—CATTLE, 3 to 6 dr. (followed by a purging drench);—HOGS, 5 to 15 gr.;—SHEEP, 15 to 30 gr.;—DOGS (small ones), 10 to 30 gr., (middle-sized) 20 to 44, or even 60 gr., (large) ⁄4 to 1 dr., or even 2 dr.

Aloes is also used in dyeing; and as a colouring matter in stains, lacquers, and varnishes. Aloes, and several of its preparations, are likewise extensively employed to adulterate porter.

Var. These, arranged in the order of their reputed medicinal value, are—Socotrine, Hepatic, Barbadoes, Cape, &c.; and alphabetically, as given below:—

Aloes, Barba′does. Syn. Aloes in Gourds; Al′oë Barbaden′sis, L., Ph. L. & E. Imported from Barbadoes and Jamaica, usually in gourds; sometimes in boxes. The best is the inspissated juice of the cut leaf of aloë vulga′′ris; an inferior quality is prepared from the decoction.—Char., &c. Opaque, lustreless, of a liver colour, a little tending to black, with a bitter nauseous taste, and a very disagreeable odour, especially when breathed on; powder a dull olive-yellow. It is the ‘hepatic’ aloes of most continental writers, and said to be the Αλοη of Dioscorides. It is more active than the other varieties of aloes; but is also more apt to occasion hæmorrhoids, and to gripe, than any of them.

Aloes, Cab′alline (-līne.) Syn. Fœt′id aloes, Horse a.; Aloë caballi′na, A. Guinien′sis, L.; Aloès Caballin, Fr. From aloë In′dica (O’Shaughnessy); or from aloë spica′ta by long and careful boiling. (Lindley.) Used only by farriers. Scarcely known in English commerce.

Aloes, Cape. Syn. Aloë Capen′sis, A. lu′cida (Geiger), L. Imported from the Cape of Good Hope, and obtained from aloë spica′ta, and other Cape species. Odour stronger and even more disagreeable than that of Barbadoes aloes; colour deep greenish-brown; appearance shining and resinous; fracture generally glassy; powder a lively greenish-yellow; almost completely soluble in boiling water, decoction paler than that of other kinds. It is weaker than Barbadoes or even hepatic aloes, and is more apt to gripe, &c., than the latter. A finer kind, known as ‘Bethelsdorp aloes,’ imported from Algoa Bay, is more of a liver colour, and softer than the preceding, and hence often called Cape hepatic-aloes.

Aloes, Hepat′ic. Syn. Bombay’ Aloes*, East-India a.*, Liver-coloured Socotrine a.*; Aloë hepat′ica, Ph. L. & D.; A. In′dica, Ph. E. Imported from Bombay and Madras. It is usually said to be obtained from “uncertain species of aloes;” but it is almost certain that it is “the juice of the Socotrine aloes plant which has been solidified without the aid of artificial heat.”—Char., &c. “Opaque, of a liver colour, bitter taste, and an unpleasant odour.” (Ph. L.) It is less odorous, darker coloured, and more opaque than Socotrine aloes; its powder has also a duller colour, and weak spirit leaves much undissolved matter. Its decoction on cooling frequently deposits a yellow powder. The finer and brighter varieties of hepatic aloes are commonly sold for ‘Socotrines,’ and their medicinal virtues are nearly similar. (See below.)

Aloes, In′dian (various);—1. Deep brown or black, very opaque, and less soluble than ordinary aloes. Scarcely known in commerce.—2. Several varieties ranging in character from ‘Cape aloes’ to ‘hepatics,’ and occasionally to ‘Barbadoes,’ obtained from several species.

Aloes, Mo′cha (-kăh). Syn. Aloë de Mochâ, L. Imported from Muscat. An inferior kind of Indian aloes. (Christison.) It is obtained from the same plant as produces genuine hepatic aloes. (Lindley.) It holds an intermediate position between ‘Cape’ and ‘hepatics,’ but contains much impurity; the latter often amounting to upwards of 25%. Some specimens are, however, of excellent quality. When melted and ‘doctored,’ it is sold for Barbadoes, hepatic, and even Socotrine aloes.

Aloes, Soc′otrine (-trĭn; sŭk′-‡). Syn. Soc′otorine aloes, Smyr′na a., Tur′key a.; Aloë Socotri′na, Ph. L.; Aloë, Ph. L. 1836; A. Socotri′na, Ph. E. “The juice of the cut leaf of uncertain species hardened by the air.” (Ph. L.) Genuine Socotrine aloes is generally supposed to be obtained from aloë spica′ta; but is referred by De Candolle to a distinct species, a. Socotri′na; and by Martius, also to a. purpuras′cens. Formerly this variety was brought from the Island of Socotra or Zocotora (hence the name), by way of Smyrna and Malta; but it is now chiefly obtained from Bombay and Madras.—Char., &c. Colour garnet red to golden red; smell peculiar and aromatic, not unlike a decaying russet apple, especially when fresh-broken, or breathed on, or warmed; taste permanently and intensely bitter; fracture conchoidal; softens in the hand, and becomes adhesive, yet retains considerable brittleness; powder bright golden-yellow colour; central portions of the lumps often soft, especially when first imported. “It is brittle, bitter, of a reddish-brown colour, and an aromatic odour. Light permeates thin recently broken laminæ.” (Ph. L.) “In thin pieces, translucent and garnet red; almost entirely soluble in spirit of the strength of sherry. Very rare.” (Ph. E.)

Socotrine aloes are always preferred for medicinal purposes, and are the only variety used in perfumery, varnishes, and other nice purposes in the arts.

Aloes, Strained. Syn. Melted Aloes; Aloë cola′ta, L. Proc. 1. The aloes are melted in a copper pan, by the heat of steam or a water bath, and are then pressed through a strong hair or wire sieve, and allowed to cool.

2. As above, but with the addition of about twice its weight of water; the decoction being strained and evaporated.

Obs. Mocha, Indian, and other common aloes, treated in this way and coloured, are frequently sold for melted or strained ‘Socotrines’ and ‘hepatics.’ The colouring matter usually employed is the precipitated carbonate of iron (sesquioxide), or Venetian red, in very fine powder, with, sometimes, a little annatto. This fraud is not readily detected by mere inspection, by those unaccustomed to these matters; and hence the impunity with which it is perpetrated.

The object in melting aloes is to deprive it of the foreign matters, as sand, leaves, pieces of wood, &c., which the commoner kinds generally contain in large quantities. The action of the heat drives off much of their nauseous smell, at the same time that it deepens their colour, and renders their appearance more translucent and resinous, to the disguise of their original nature. The operation, on the large scale, is usually carried on at night, in consequence of the horribly nauseous fumes evolved, which may be smelt at a great distance, and contaminate the clothes of those engaged in it for a long time afterwards.

AL′OES HEMP. A plant growing in Peru, the East and West Indies, and Mexico (A. Americana, A. vivapara, A. fœtida, &c.), where the leaf is cultivated for its fibre, which is generally of a yellowish-white colour, and used for rope-making.

AL′OES WOOD. Syn. Al′oe-wood; Eaglewood; Agal′lochum (-kŭm), Lig′num al′oës, L. agal′lochi, L. a. ve′′ri, L. aq′uilæ, L. aspal′athi, L.; Agalloche, Bois d’aloès, Fr.; Aloeholz, Ger.; Calam′bac, Calam′bouc, Ind.; Xylo-al′oës†. A name applied to the wood of alöex′ylon agal′lochum (Lam.), a leguminous tree of Cochin China; and, though apparently less correctly, to that of aquila′′ria agallochum and a. ova′ta (Lour.), trees of tropical Asia, belonging to a different nat. order. Both are highly fragrant and aromatic; used in fumigations and pastilles, and occasionally by cabinet makers and inlayers. The essential oil of the wood, dissolved in spirit, was regarded by Hoffmann as one of the best cordials and invigorants known. The same has also been said of a tincture of its resin.

The same name and synonyms are popularly applied to the resin of the above woods (ALOES-WOOD RESIN), of which there are two varieties:—the one, light and porous, and filled with a highly fragrant resinous substance; the other, denser and less resinous. It is an oily concretion in the centre of the tree, the result of disease, which gradually hardens, and, in time, kills it. It is highly fragrant, and is said to be nervine, cephalic, cardiac, and stimulant. The powder is regarded as tonic and astringent. Of all perfumes this is said to be the one most esteemed by oriental nations.

ALOE′TIC. Syn. Aloët′icus, L.; Aloétique, Fr. Of or belonging to aloes. In medicine, pharmacy, &c., applied to any preparation containing aloes as a characteristic ingredient; made or obtained from aloes. Substantively, an aloetic medicine.

AL′OIN (-o-ĭn). C17H18O7. [Eng., Fr.] Syn. Al′öin; Aloï′na, L. The Messrs T. & H. Smith, of Edinburgh, have applied this name to a crystalline substance, which they assert to be the pure cathartic principle of aloes. Their process is to evaporate to the consistence of a syrup, in vacuo, a solution obtained by exhausting a mixture of aloes and sand, with cold water, and then to set it aside for a few days. The resulting dark crystalline mass is purified by pressure between folds of bibulous paper, and repeated crystallisation from hot water. Barbadoes aloes are commonly used for the purpose; but soft or semi-liquid Socotrine aloes, or the unevaporated Socotrine-aloes juice, is probably its best source. Tilden gives the following process for the preparation of aloin:—The aloes crushed small is to be dissolved in nine or ten times its weight of boiling water acidified with sulphuric acid. After cooling and standing for a few hours, the clear liquid is decanted from the resin, and evaporated. The concentrated solution deposits a mass of yellow crystals, which can be purified by washing, pressure, and recrystallisation from hot spirit. After several recrystallisations the aloin is obtained in the form of beautiful yellow needles, which are pretty soluble in water and in alcohol, but soluble with difficulty in ether.—Dose, 1 to 2 gr.

ALOPE′CIA (-sh′ă). [L.] Syn. Al′opecy, Fox′-evil; Alopécie, Fr.; Fuchsraude, Ger. In pathology, baldness from disease, often extending to the beard and eyebrows; as distinguished from ‘calvities,’ or ordinary baldness arising from attenuation of the scalp or defective nutrition. See Baldness.

ALPAC′A. A species of Llama, popularly known as the Peruvian Sheep, an animal intermediate between the camel and sheep, having long silky hair, nearly as fine as that of the Cashmere goat. It was introduced to the British manufacturers in 1834, when only 5700 lbs. of it was imported; but it soon became an important article of commerce, the quantity imported having gradually risen to above 2⁄4 millions of lbs. in 1853; whilst the price has risen from about 9d. to 2s. 7d. the lb., in the same time. The name is also given to fabrics woven from the wool of this animal; and to others in fine wool, made in imitation of them. The gigantic factory, &c., erected at Saltaire, Yorkshire, in 1852, for this manufacture, covers about 12 acres of land. See Llama.

ALPENKRAUTER-BRUST-TEIG (Grablowitz, Gras). Pectoral cakes of Alpine herbs. Gum arabic, 100 parts; sugar, 200 parts; extract liquorice, 1 part; saffron, ⁄8th part. Each box contains 48 lozenge-shaped yellowish cakes. Made into a mass with decoction of marsh mallow. (Hager.)

ALPENKRAUTER GESUNDHEIT’S LIQUEUR (Rudolph Bohl). Medicinal liqueur of Alpine herbs. A bottle containing 350 grammes of a liqueur which is an extract of star anise, cassia, frangula bark, centaury, chicory, gentian, and a little aloes. (Hager.)

ALPENKRAUTER-MAGENBITTER (Hauber). Stomachic bitters of Alpine herbs. A brown liqueur of bitter, spirituous, and slightly aromatic flavour, containing in 100 parts: oil of anise, 0·5; oil of cloves, 0·5; aloes, 1·5; alcohol, 40; water, 50. 157 grammes in each bottle. (Wittstein.)

ALPHA-ORSELL′IC ACID. See Orsellic Acid.

ALPINE ROSE SOAP, SWISS. A preservative against syphilitic infection (G. A. Sarpe, Zurich). A glass cylinder corked and sealed, about 2 inches long, and containing a hard brownish-grey mass weighing 12 grammes, prepared thus:—Ammonia, 1 part; sublimate, 3 parts; tannin, 2 parts; chloride of lime, 24 parts; Castile soap, 190 parts; oil of cloves, 1 part; spirit of wine, q. s. (Hager.)

AL′QUIFOU (-ke-fōō). Syn. Black lead-ore, Potter’s ore. A native sulphide of lead used by potters to give a green glaze to coarse wares.

ALSTONIA SCHOLARIS. (Ind. Ph.) Habitat. Common in forests throughout India.—Officinal part. The bark (Alstoniæ cortex). It occurs in thick, irregular, more or less contorted pieces, easily broken. It consists of a rough greyish epidermis, investing a buff or pale cinnamon-coloured bark; internally, still lighter in colour, and of a spongy texture, having a very bitter taste, but devoid of odour.—Properties. Astringent, tonic, anthelmintic, antiperiodic—Therapeutic uses. In chronic diarrhœa and the advanced stages of dysentery; also as a tonic in debility after fevers, and other exhausting diseases.—Dose. 3 to 5 grains, either alone or combined, in bowel affections, with small doses of ipecacuanha and extract of gentian.—Preparations. Tincture of Alstonia (Tinctura Alstoniæ). Take of alstonia bark, bruised, 2⁄2 ounces; proof spirit, 1 pint. Macerate for seven days in a closed vessel, with occasional agitation; filter, and add sufficient proof spirit to make 1 pint. Or prepare by percolation, as Tincture of Calumba.—Dose, 1 to 2 fluid drachms.

Alstonia, Infusion of. (Infusum Alstoniæ.) Take of alstonia bark, bruised, ⁄2 an ounce; boiling water, 10 fluid ounces. Infuse in a covered vessel for an hour and strain.—Dose. From 1 to 2 fluid ounces twice or thrice daily. A good serviceable tonic.

AL′TERATIVE (awl′-tĕr-ă-tĭv). Syn. Al′terant*; Al′terans (ăl′-), L.; Altérant, Altératif, Fr. In medicine, having power to alter; applied to substances and agents which occasion a change in the habit or constitution, and thus re-establish the healthy functions of the body, or any part of it, without producing any sensible evacuation or other obvious effect.

ALTERATIVE EXTRACT, or GOLDEN MEDICAL DISCOVERY (Dr Pierce, Buffalo), for the cure of all severe, acute, chronic, or long-standing coughs, inflammations, hoarseness, scrofulous, and syphilitic diseases. A clear light-brown fluid, 220 grms., composed of 15 grms. purified honey, 1 grm. extract of lettuce, 2 grms. laudanum, 100 grms. of proof spirit tasting of fusel oil and wood spirit, and 105 grms. water. (Hager.)

AL′TERATIVES (-tĭvz). Syn. Alteran′tia, L.; Altératifs, &c., Fr. Alterative medicines or agents. The preparations of mercury and iodine, when properly administered, are the most useful members of this class; and are those which are now the most generally employed.

ALTHE′IN (ăl-thē′-ĭn). Syn. Althæ′ina, L. The name given by Braconnot to a substance identical with asparagin, which he discovered in the ‘marsh-mallow’ (althæ′a officina′lis, Linn.).

ALTHOFF WATER (aqua mirabilis), for torpid ulcers. Wine vinegar, 750 parts; sulphate of copper, 100 parts; potash, 25 parts; ammonia, 30 parts; salt of sorrel, 8 parts; French brandy, 375 parts. Digest for a few days in a glass vessel and distil to dryness from a glass retort. (Wittstein.)

AL′UDEL (-ū-). In chemistry, a pear-shaped glass or earthen pot open at both ends, formerly much used for connecting other vessels in the process of sublimation. A number of them joined together are still employed for the distillation of quicksilver, in Spain.

AL′UM K2SO4.Al2(SO4)3.24Aq. Syn. Pot′ash-alum, Sul′phate of aluminum and potassium, Common alum; Alu′men, A. potas′sicum, L.; Alun, Sulfate d’alumine et de potasse, Fr.; Alaun, Ger.; Alume, Ital.

The principal alum-works in England, until recently, were those of Lord Glasgow, at Hurlett and Campsie, near Glasgow, and those of Lords Dundas and Mulgrave, at Whitby, Yorkshire (est. 1600); but those of Mr Spence, at Manchester, and at Goole (Yorkshire), and of Mr Pochin, at Manchester, are now among the largest, if they be not actually the largest in the world. There are also extensive alum-works at and near Newcastle-on-Tyne; but none of importance, that we know of, in any other part of these realms.

Nat. hist. Alum is found native in some places (NATIVE ALUM), either effloresced on the surface of bituminous alum-schist (Göttwigg, Austria); or united with the soil in the neighbourhood of volcanoes (Solfatara, Naples); when it may be obtained by simple lixiviation and evaporation, a little potash being commonly added to convert the excess of sulphate of alumina present into alum. It is also found in certain mineral waters (East Indies).

Sources. The alum of commerce is usually obtained from schistose pyritic clays, commonly termed alum-ores, aluminous shale, a.-schist, &c.; and from alum-rock, a.-stone, or alunite. At La Tolfa, Civita Vecchia, where the best Roman-alum is produced, the source is stratified alum-stone. On the Continent, and in Great Britain, it is generally pyritaceous clays, volcanic aluminous ores, aluminous shale, or alum-slate. These minerals contain sulphide of iron, alumina, bitumen or carbon, and frequently a salt of potassium. Of late years large quantities of alum have been prepared on the banks of the Tyne from aluminous clay.

Prep. The manufacture of alum is technically said to be conducted according to the natural process when prepared from alum-schist or alum-ore; and according to the artificial process when made by acting on clay with sulphuric acid, and adding a potassium salt to the resulting lixivium. The manufacture of alum and of sulphate of alumina from such materials as contain only alumina, to which consequently sulphuric acid and alkaline salts have to be added, has come largely into practice in England. The materials employed are, in addition to clay, cryolite or Greenland spar, a fluoride of aluminum and soda; bauxite, a hydrate of alumina, of more or less purity; and slag. The following are the details of these processes:—

a. From ALUM-ORE, ALUMINOUS SCHIST, or SHALE, &c.:—

1. The mineral (alum-ore, a.-schist, &c.) is placed in heaps, and moistened from time to time with water, when it becomes gradually hot, and falls into a pulverulent state. This decomposition commonly occurs either wholly, or partially, on the floor of the mine. If the ore does not possess this property on mere exposure to air and moisture, it is broken into pieces and laid upon a bed of brushwood and small coal, to the depth of about four feet, when the pile is fired and fresh lumps of the alum-mineral thrown on, until the mass becomes of considerable height and size. The combustion, as soon as established, is conducted with a smothered fire, until the calcination is complete; care being taken to prevent fusion, or the disengagement of either sulphurous or sulphuric acid, from contact between the ignited stones and the carbonaceous fuel. To promote these ends the pile, at the proper time, is ‘mantled’ (as the workmen call it) or covered with a layer of already calcined and exhausted ore, in order to protect it from high winds and heavy rains; as also to moderate the heat, and let it proceed gradually, so that the sulphur present may not be lost or wasted by volatilisation. The roasting is finally checked by a thicker ‘mantling,’ and the whole allowed to cool. By this time the pile has usually lost about one half its bulk, and become open and porous in the interior, so that the air can circulate freely through the mass; the latter, in dry weather, as the heap cools, being usually promoted by sprinkling a little water on it, which, by carrying down some of the saline matter, renders the interior still more open to the atmosphere. The whole, when cold, or nearly cold, is, if necessary, still further exposed to the action of air and moisture. The time required to calcine the heap properly, including that taken by the burned ore to cool, varies, according to its size and the state of the weather, from three to nine, or even twelve months. The residuum of the calcination is next placed in large stone or brick cisterns, and edulcorated with water, until all the soluble portion is dissolved out; the solution is then concentrated in another stone cistern, so made that the flame and heated air of its reverberatory furnace sweep the whole surface of the liquor. (See engr.) The evaporation is continued until it just barely reaches the point at which crystals are deposited on cooling; when it is run off into coolers. After the sulphate of iron, always present, has been deposited in crystals, the mother-liquor, containing the sulphate of aluminum, is run into other cisterns, and a saturated solution of chloride of potassium, or of sulphate of potassium, or (sometimes) impure sulphate or carbonate of ammonium, or a mixture of them, is added until a cloud or milkiness ceases to be produced on addition of more. It is next allowed to settle and get thoroughly cold, and the supernatant ‘mother-liquor’ being drawn off with a pump or syphon, the precipitate, which is alum in the form of minute crystals (technically termed ‘flour’), is well drained, and subsequently washed by stirring it up with a little very cold water, which is then drained off, and the operation repeated a second time with fresh water. A saturated solution of the pulverulent alum (‘flour’) is next formed in a leaden boiler, and the clear portion is run or pumped off, while boiling hot, into crystallising vessels, called roaching casks (see engr.), the staves of which are lined with lead, and nicely adjusted to each other. After the lapse of a week or ten days, the hoops and staves of these ‘casks’ are removed, when a thick crust of crystallised alum is found, which exactly corresponds in form and size to the interior of the cask. A few holes are then made in the sides of this mass, near the bottom, to allow the contained mother-liquor to drain off, after which the whole is broken up and packed in casks for sale. Sometimes the alum thus obtained, or the lower portion of it, is washed with a little very cold water, and, if discoloured, or small or slimy, is purified by a second crystallisation.

2. As ammonia-alum (Spence’s process; see below), but using a potash-salt as the precipitant, either wholly or in part, instead of ammonia; and, in the latter case, supplementing the deficiency of potash with ammonia, as there explained.

b. From ALUMINOUS CLAY and OIL OF VITRIOL:—

1. Clay, free or nearly free from carbonate of lime and oxide of iron, is chosen for this purpose. It is moderately calcined (in lumps) in a reverberatory furnace, until it becomes friable; great care being taken that the heat be not sufficient to indurate it, which would destroy its subsequent solubility. It is next reduced to powder, sifted, and mixed with about 45% of its weight of sulphuric acid (sp. gr. 1·45), the operation being conducted in a large stone or brick basin arched over with brickwork. Heat is then applied, the flame and hot air of a reverberatory furnace being made to sweep over the surface of the liquor. The heat and agitation are continued for 2 or 3 days, when the mass is raked out and set aside in a warm place for a few weeks (6 to 8), to allow the acid the more perfectly to combine with the clay. At the end of this time the newly-formed sulphate of alumina is washed out, the solution evaporated until of a sp. gr. of about 1·38 (1·24 for ‘ammonia-alum’), and the salt of potash added. The remaining operations resemble those above described. Good alum may be produced by this process at about two thirds the cost of rock or mine alum.

2. (Process of Mr Pochin.) Fine China clay is heated in a furnace, and mixed with a suitable proportion of sulphuric acid; the latter being considerably diluted with water, in order to moderate its action, which would otherwise be far too violent. The mixture is then passed into cisterns furnished with movable sides, where, in a few minutes, it heats violently and boils. The thick liquid gradually becomes thicker, until it is converted into a solid porous mass; the pores being produced by the bubbles of steam which are driven through it, owing to the heat resulting from the reaction of the ingredients on each other. This porous mass (ALUM-CAKE; CONCENTRATED ALUM) appears perfectly dry, although retaining a large amount of combined water. It also contains all the silica of the original clay, but in such a state of fine division, that the whole appears homogeneous; whilst it imparts a dryness to the touch which can scarcely be given to pure sulphate of alumina. From this substance a solution of pure sulphate of alumina is easily obtainable by lixiviation, and allowing the resulting solution to deposit its silica before using it, but for many purposes the presence of the finely divided silica is not objectionable. The sulphate of alumina solution so obtained is adapted to all the purposes in dyeing for which alum is now employed; the sulphate of potash or of ammonia in the latter being an unnecessary constituent, and one merely added to facilitate the purification and subsequent crystallisation of the salt. To obtain ALUM from the porous alum-cake, the proper proportion of acid having been used in its preparation, or subsequently added, it is only necessary to precipitate its concentrated solution with a strong solution of a salt of potash, or of ammonia, or a mixture of them, and to otherwise proceed as before.

Ratio. In the above process the sulphide of iron of the shale or schist is converted by atmospheric oxygen into sulphate of iron and sulphuric acid; the sulphuric acid decomposes the clay, setting silica free, and producing sulphate of aluminum. The sulphate of iron is mostly got rid of by concentrating the solution of the mixed sulphates, and the mother-liquors are converted into alum by the addition of the salt of potassium. When chloride of potassium is used, it yields chloride of iron and sulphate of potassium, the latter combining with the sulphate of aluminum, and the former remaining behind in the mother-liquor. See Alums (in Chemistry).

Comp. Potassium alum has the formula K2SO4.Al2(SO4)3.24Aq.

c. From Cryolite.

1. (Thomson’s method.) Decomposition of cryolite by ignition with carbonate of lime. From the ignited mass the aluminate of soda is obtained by lixiviation with water, and into the solution carbonic acid gas is passed, when there result precipitated hydrated gelatinous alumina and carbonate of soda, which remains in solution. If it be desired to obtain the alumina as an earthy compact precipitate, bicarbonate of soda is used instead of carbonic acid. While the clear liquor is boiled down for the purpose of obtaining carbonate of soda, the precipitated alumina is dissolved in dilute sulphuric acid; this solution is evaporated for the purpose of obtaining sulphate of alumina (the so-called concentrated alum), or the solution after having been treated with a potassa or an ammonia salt is converted into alum.

2. (Sauerwein’s method.) Decomposition of cryolite by caustic lime by the wet way. Very finely ground cryolite is boiled with water and lime, the purer the better, and as free from iron as possible, in a leaden pan. The result is the formation of a solution of aluminate of soda, and insoluble fluoride of calcium (lime). When the fluoride of calcium has deposited, the clear liquid is decanted, and the sediment washed, the first wash-water being added to the decanted liquor, and the second and third wash-waters being used instead of pure water at a subsequent operation. In order to separate the alumina from the solution of aluminate of soda, there is added to the liquid while being continuously stirred very finely pulverised cryolite in excess, the result of the decomposition being alumina and fluoride of sodium, (soda). When no more caustic soda can be detected in the liquid, it is left to stand for the purpose of becoming clear. The clarified solution of fluoride of sodium is then drawn off, and the alumina treated as above described. The solution of fluoride of sodium having been boiled with caustic lime yields a caustic soda solution, which having been decanted from the sediment of fluoride of calcium is evaporated to dryness. Recently the fluoride of calcium occurring as a by-product has been used in glass-making.

3. The decomposition of cryolite by sulphuric acid yields sulphate of soda convertible into carbonate by Leblanc’s process, and sulphate of alumina free from iron. This method of decomposing cryolite is, however, by no means to be recommended, as owing to the liberation of hydrofluoric acid, peculiarly constructed apparatus are required, whilst the sulphate of soda has to be converted into carbonate.

d. From Bauxite. This mineral, occurring in some parts of Southern France, in Calabria, near Belfast, and in other parts of Europe, consists essentially (viz. 60 per cent.) of hydrate of alumina, more or less pure. In order to prepare alums and sulphate of alumina from it, the mineral is first disintegrated by being ignited with carbonate of soda, or with a mixture of sulphate of soda and charcoal; in each case the lixiviation of the ignited mass yields aluminate of soda, from which, by the processes already described under “Cryolite,” alum, or sulphate of alumina, and soda are prepared.

e. From blast-furnace slag. Lürmann recommends the slag to be decomposed by means of hydrochloric (muriatic) acid. From the resulting solution of chloride of aluminum the alumina is precipitated by carbonate of lime, any dissolved silica being precipitated at the same time. The alumina is dissolved in sulphuric acid, leaving the silica.

Prop. Alum crystallises in regular octahedrons, often with truncated edges and angles; (see engr.); and sometimes in cubes, but only when there is a deficiency of acid in its composition, with the alkali in slight excess of the proper quantity. (Löwel.) It is slightly efflorescent in dry air: soluble in 18 parts of cold water, and in rather less than its own weight of boiling water; tastes sweet, acidulous, and very astringent; is styptic; and reddens litmus. When heated it melts, loses its water of crystallisation, and becomes white and spongy (DRIED ALUM); a strong heat, short of whiteness, decomposes it, with the evolution of oxygen and a mixture of sulphuric and sulphurous anhydride; calcined with carbonaceous matter it suffers decomposition, and furnishes a pyrophoric residuum (Homberg’s pyro′phorus). Ignited with alkaline chlorides, hydrochloric acid is liberated; which also occurs when their concentrated solutions are boiled together. Ammonia precipitates pure hydrate of aluminum from potassium alum; but only a subsulphate from the simple sulphate of alumina. Sp. gr. 1·724; but, when containing ammonia, often so low as 1·710.

Tests, &c. It is easily recognised by its crystalline form, its taste, and by its complete solubility in water. Its aqueous solution gives a white gelatinous precipitate soluble in excess; a platinum wire moistened with the solution imparts a violet colour to the blowpipe flame; and chloride of barium gives a white precipitate insoluble in nitric acid.

Pur. When pure, its solution is not darkened by tincture of galls, sulphuretted hydrogen or ferrocyanide of potassium; neither does it give any precipitate with solution of nitrate of silver. Heated with caustic potassa, or quick-lime, it does not evolve fumes of ammonia.

Adult., &c. The principal impurity, and one which renders alum unfit for the use of the dyer, is iron. This may be readily detected by the blue precipitate it gives with ferrocyanide of potassium, or the black precipitate with sulphide of ammonium, which are very delicate tests. Lime, another very injurious contamination, may be detected by precipitating the alumina and iron (if any) with ammonia, and then adding oxalate of ammonia to the boiled and filtered liquid. The liquid filtered from the last precipitate (oxalate of lime) may still contain magnesia, which may be detected by the white precipitate caused on the addition of an alkaline phosphate. Common alum frequently contains ammonia, from urine, or the crude sulphate of the gas-works, having been employed in its manufacture. Powdered alum is frequently adulterated with common salt, in which case it gives a white curdy precipitate with nitrate of silver, turning black by exposure to the light.

Phys. eff. &c. In small quantities alum acts as an astringent; in larger doses as an irritant. It acts chemically on the animal tissues and fluids, is absorbed, and has been discovered in the liver, spleen, and urine (Orfila), the last often becoming acid (Kraus). Externally, it is astringent. The almost general use of alum by the English bakers is one of the most fertile sources of dyspepsia and liver and bowel complaints in adults; and of debility and rickets in children. Bad teeth and their early decay is another consequence of the daily use of alum in our food. The bone matter (phosphate of lime) of bread, instead of being assimilated by the system, is either wholly, or in part, converted into a salt of alumina, which is useless and incapable of appropriation. When alum has been taken in poisonous doses an emetic should be given, followed by warm diluents and demulcents, containing a little carbonate of soda; and subsequently by a purgative.

Uses, &c. The applications of alum in the arts and manufactures are numerous and important. It is used to harden tallow and fats; to render wood and paper incombustible; to remove greasiness from printers’ blocks and rollers; to prepare a paper for whitening silver and silvering brass in the cold; to help the separation of the butter from milk; to purify turbid water; to dress skins; to fix and brighten the colours in dyeing; to make lake and pyrophorus, &c., &c. It is also extensively used for clarifying liquors, and for many other purposes connected with the arts and everyday life. In medicine, alum is used as a tonic and astringent, in doses of 5 to 20 gr.; as a gargle (1 dr. to ⁄2 pint of water); and as a collyrium and injection (10 to 15 gr. to 6 oz. of water). In lead colic, ⁄2 to 1 dr. of alum (dissolved in gum-water), every 3 or 4 hours, is said to be infallible. Powdered alum is frequently applied with the tips of the fingers, in cases of sore throat and ulcerations of the mouth, &c. A teaspoonful of it is said to be one of the very best emetics in croup. (Dr Meigs.) Alkalies, alkaline carbonates, lime, magnesia, acetate of lead, astringent vegetables, &c., are incompatible with it.

Gen. commentary. In addition to the particulars of its manufacture given above, we may add, that the plan of getting rid of the ferric salts there referred to has to some considerable extent been successfully replaced by that of precipitating the alum, instead of the sulphate of iron, by adding alkaline matter to the lixivium. The crystalline precipitate is purified by draining, re-solution, and re-crystallisation; whilst the sulphate of iron and Epsom-salts contained in the mother liquor are obtained by subsequent evaporation and crystallisation; after which a fresh crop of alum may be got from it, by the use of an alkaline precipitant, as before.

In estimating the strength of his solution the alum-maker takes as a standard a measure or sp. gr. bottle capable of holding exactly 80 pennyweights of distilled water. The excess of the weight of liquor, in pennyweights, over 80, or that of water, is called so many ‘pennyweights strong.’ Thus one of 90 pennyweights (90 dwt.) is said to be ‘10 dwt. strong,’ or simply, ‘one of 90 dwt.’ These numbers correspond to 2⁄2 degrees of Twaddle’s hydrometer, and may easily be found by dividing Twaddle’s degrees by 2·5 or 2⁄2; or by multiplying them by 4, and pointing off the right-hand figure of the product for a decimal. The result is in alum-makers’ pennyweights.

By a patent now expired (Weisman’s, 1839) the ferric salts are precipitated by the addition of a solution of ferrocyanide of potassium (prussiate of potash); after which the supernatant clear liquor, which is now a solution of nearly pure sulphate of alumina, is decanted, and evaporated for future operations, until it either forms, on cooling, a concrete mass, which is moulded into bricks or lumps, for the convenience of ‘packing,’ or until it is sufficiently concentrated to be converted into ALUM by the addition of a salt of potash or of ammonia in the usual manner. The product, in each case, is perfectly free from iron. By a like addition of the ferrocyanide to a solution of ordinary sulphate of aluminia or alum, the dyer may himself easily render them free from iron, or iron-alum; when, as mordants for even the most delicate colours, they are equal to the very best Roman alum.

Another process has been patented (Barlow & Gore, 1851) for the manufacture of alum from the ash or residue of the combustion of Boghead-coal, which, though hitherto regarded as almost valueless, actually contains about 30% of alumina. It has not, however, been found a convenient material for the purpose.

By the latest and most approved processes the least possible quantity of boiling water or liquor is employed for making the solutions, so that they may crystallise without evaporation, and thus economise fuel; and the mother-liquors of previous operations are constantly employed for this purpose, when possible. Nor is anything which is convertible to use, from the drainage of the heaps, to the liquor and slime of the roaching casks, allowed to be wasted.

By whatever process, or from whatever materials alum is obtained, it is absolutely necessary for the successful and economical conduct of its manufacture, that the precise composition of the mineral or minerals employed should be exactly known. This can only be determined by actual analysis, which should be extended to several parts of the same bed, and particularly to the upper and lower strata, which frequently differ in composition from each other, and thus require different treatment, or may be most advantageously employed in combinations with each other. The necessity of this will be seen by reference to the composition of the following minerals, of which the top contains a larger proportion of iron-pyrites than the bottom, and the two require to be mixed, to equally diffuse the sulphuric acid generated by the calcination, &c., to which they are subjected.

The following is the per-centage composition of certain alum shales:—

Whitby, Yorkshire. (Richardson.)

Top rock. Bottom rock.

Sulphide of iron (pyrites) 4·20 8·50

Silica 52·25 15·16

Protoxide of iron 8·49 6·11

Alumina 18·75 18·30

Lime 1·25 2·15

Magnesia ·91 ·90

Oxide of manganese traces traces

Sulphuric acid (SO3) 1·37 2·50

Potassa ·13 traces

Soda ·20 traces

Chlorine traces traces

Coal 4·97 8·29

Water 2·88 ·00

Loss 4·60 (?)

100· 100·

Campsie, near Glasgow. (Ronalds.)

Top rock. Top rock. Bottom rock.

Sulphide of iron (pyrites) 40·52 38·48 9·63(?)

Silica 15·40 15·41 20·47(?)

Protoxide of iron ... ... 2·18

Alumina 11·35 11·64 18·91(?)

Lime 1·40 2·22 ·40

Magnesia ·50 ·32 2·17

Oxide of manganese ·15 ... ·55

Sulphuric acid ... ... ·05

Potassa ·90 ... 1·26

Soda ... ... ·21

Carbon or bituminous matter 27·65(?) 28·80 (?)

Coal ... ... 8·51

Water ... ... 8·54

Loss 2·13(?) 3·13 1·59(?)

100· 100· 100·

Alum-rock, or alum-stone, is a species of impure alunite, and is not of very common occurrence. That of Tolfa, near Civita Vecchia, according to Klaproth, consists of—

Silica 56·5

Alumina 19·

Sulphuric acid (SO3) 16·5

Potassa 4·

Water 3·

Loss 1·

100·

which exhibits an excess of about 3% of sulphuric acid, and about 14% of alumina, more than are requisite to form alum with the 4% of potassa; proportions which, therefore, require to be supplemented with a potassium salt during the process of manufacture. The alum-stone of Mont d’Or contains, according to Cordier, 1·4% of oxide of iron.

The presence of lime in alum-ore is most prejudicial, owing to its affinity for sulphuric acid being greater than that of either alumina or iron. Ores containing it in any quantity are, therefore, unfitted for the manufacture of alum. Magnesia is also prejudicial; but in this case the sulphate of magnesia left in the mother-liquors is not wholly valueless, as it may be crystallised and sold as ‘Epsom-salt,’—a thing which is actually done in some English alum-works.

The potash-salt employed by the alum-makers is either the sulphate or the chloride—chiefly the latter; its sources being the waste liquor of soap-works, saltpetre refineries, and glass-houses. Wood-ashes, although rich in potash, do not answer well unless freed by lixiviation from the large amount of carbonate of lime which is always present in them.

The ammonia-salt used in making alum is generally the crude sulphate prepared from the ammoniacal liquor of gas-works, or that from the manufacture of sal-ammoniac by the destructive distillation of animal matter. Both these liquors may be used without previous conversion into sulphate of ammonia whenever there is an excess of sulphuric acid in the aluminous solution.

Soda-salts are seldom, if ever, used as precipitants in the manufacture of alum, on account of the easy solubility of the resulting SODA-ALUM—a property which unfits them for this purpose. See Alums, Ammonia, Dyeing, Mordants, Potash, Sulphuric Acid, &c. (also below).

Alum, Ammonia. (NH4)2SO4 . Al2(SO4)3 . 24 Aq. Syn. (Alumen; Alum; B. P.), Alu′men Ammonia′tum, L.; Alun d’ammoniaque, A. ammoniacal, Fr. This is an alum in which the sulphate of potassium is replaced by an equivalent of sulphate of ammonium. It is prepared by adding crude sulphate of ammonium to solution of sulphate of aluminum; or gas-liquor, putrid urine, &c., to the acid-sulphate.

Much of the common alum, especially that prepared on the Continent, contains both potassium and ammonium; and recently enormous works for its manufacture have been established in England. As an astringent, and as a source of alumina in dyeing, it resembles potash-alum (i. e. ordinary alum). It may, however, be readily distinguished from the latter by the fumes of ammonia which are evolved when it is moistened and triturated, or heated, with caustic potassa or quick-lime; and by the residuum of its exposure to a white heat being pure alumina. See Alum (antè).

Alum, Basic. A variety of alum found native at Tolfa. On calcination and subsequent lixiviation it yields ordinary alum. A like substance falls as a white powder, when newly precipitated alumina is boiled in a solution of alum.

Alum, Baumé’s. Alum-white. See White Pigments.

Alum, Dried; Alum, Burnt. Syn. Alu′men us′tum, A. exsicca′tum (B. P.); Alun Sec, Fr.; Gebrannter alaun, Ger.; Alume calcinato, Ital. Alum deprived of its water of crystallisation by heat.

Prep. Take of alum, 4 oz. Heat the alum in a porcelain dish or other suitable vessel, till it liquefies, then raise and continue the heat, not allowing it to exceed 400°, till aqueous vapour ceases to be disengaged, and the salt has lost 47 per cent. of its weight. Reduce the residue to powder, and preserve it in a well-stopped bottle.

Prop., &c. Similar to those of common alum, but it is rather more astringent, and is less soluble. When moistened, or placed in contact with water, it resumes its water of crystallisation with evolution of heat.—Dose, 10 to 20 gr.; in colic (especially painters’ colic), hæmoptysis, &c. It is chiefly used as an escharotic, to destroy ‘proud flesh,’ &c. It must be kept in a stoppered bottle.

Alum, Chrome. See Alums (in Chemistry).

Alum, I′ron (-ŭrn). Syn. Alu′men Fer′ricum, Sul′phas fer′ri et potas′sæ, Fer′ri perox′idi potassio-sul′phas, &c., L.

Comp. K2SO4 . Fe2(SO4)3.24Aq.

Prep. Take of peroxide of iron, 9 lbs.; sulphuric acid 14 lbs.; dissolve, dilute the mixture with water, q. s., and add of potassium sulphate, 10 lbs.; evaporate, and crystallise.

Prop., &c. Crystals, beautiful octahedrons of a pinkish or pale violet colour. It is strongly recommended, by Dr Tyler Smith, as a chalybeate tonic, and has been used by him, at St. Mary’s Hospital with marked success. It has also been used as a mordant, in dyeing black.—Dose, ⁄2 gr. to 5 gr.

Alum, Ro′man. Syn. Red alum*, Roach A., Roche A., Rock A.*; Alu′men Roma′num, A. ru′brum, A. ru′peum, &c., L.; Alun Romain, A. de roche, Fr.; Alume di rocca, It. In small fragments, covered with a reddish powder (ALUMEN RUBRUM VE′′RUM); originally imported from Civita Vecchia, where it occurs native. It is much esteemed by dyers from being nearly free from iron-alum. That now sold for it in England is ordinary alum coloured with Venetian red, Armenian bole, or rose-pink (ALUMEN RUBRUM SPU′′RIUM). This is done by shaking the fragments in a sieve over a vessel of hot water, and then stirring them up with the colour, until the surface is uniformly tinged with it. In genuine roach-alum the colour not only covers the surface, but also partially pervades the substance of the crystals. The name was formerly also applied to a pure white variety of alum, prepared at Tolfa; but it is now, in English commerce, exclusively given to common alum artificially coloured.

Alum, Saccharated. Alum, 6 oz., white lead 6 drms., sulphate of zinc 3 drms., sugar 1⁄2 oz. Mix the ingredients reduced to powder into a paste, with vinegar and white of egg. Used in eye waters and cosmetic washes.

Alum, So′da. Syn. Sulphas aluminæ et sodæ, L. Comp. Na2SO4 . Al2(SO4)3 . 24Aq. An alum in which the potassium sulphate of common alum is replaced by a like salt of sodium. It does not occur in commerce. (Vide suprà et infrà.)

ALUM-EARTH. Alumina.

ALUM MOR′DANTS. In dyeing, mordants having for their basis either common alum or the acetate or sulphate of aluminum. See Alums and Mordants.

AL′UM-ROOT. Syn. Amer′ican san′icle; Heu′chera (Ph. U. S.), L. The root of heuchera America′na (Linn.), a plant of North America. It is powerfully styptic and astringent; and is used chiefly as an external application in cancer.

ALUM-WHITE. See White Pigments.

AL′UMS. Syn. Alu′mina (pl. of alu′men), L. In chemistry, a term applied to a series or group of salts having potassium alum for their type, which they resemble in crystalline form and constitution.

It is found that the aluminum of common alum may be replaced by any other metal having a like nature, without affecting the leading characteristics of the salt; and further, that in the newly formed compound, as in potassium-alum, the second sulphate may also be replaced under the like conditions. All the alums crystallise in octahedrons or cubes, and they all contain the same number of molecules of water. The alums of commerce (or alums proper) all contain aluminum sulphate and an alkaline sulphate.

Prep. All the alums may be made by mixing together solutions of the respective sulphates in equivalent proportions, when crystals may be obtained by evaporation in the usual manner. The presence of sulphuric acid, in slight excess, assists their crystallisation.

AL′UMED (al′ŭmd). Mixed or impregnated with alum. In dyeing, mordanted with alum.

ALU′MEN (-l′ōō-). [L.] Alum; the pharmacopœial name of alum. (See above.)

ALUMINIUM. Syn. Aluminum (which see).

ALUMINOUS. In mineralogy, of, resembling, or containing aluminum. In chemistry, containing or obtained from alum.

ALUMINUM. [Eng., Fr., L.] Syn. Aluminium, Eng., Fr., L.; Alumium, Ger. A metallic radical or element very abundantly distributed, united with silica. Discovered by M. Wöhler, who succeeded in obtaining it as a grey metallic powder (A.D. 1827); and later (1845), under the form of globules exhibiting the leading characteristics of the metal. In 1854, M. Dumas announced to the ‘Academy of Sciences,’ that M. St. Clair Deville had procured pure aluminum from clay, and exhibited several specimens of considerable size and beauty. The result was a general impression that it might be easily obtained in any quantity, and ultimately at a reasonable price; expectations which have been only partly, though to a great extent fulfilled, owing to the expense and trouble of the process, notwithstanding recent improvements.

Prep. (M. Deville; A.D. 1854-59.)—A quantity of chloride of aluminum, varying from 200 to 300 grammes (say from 6 to 10 oz.), is introduced into a wide glass or porcelain tube, between two plugs of asbestos to retain it in position, and a current of hydrogen (thoroughly dried by passing first through concentrated sulphuric acid, and then through a tube containing fused chloride of calcium) passed over it; a gentle heat being at the same time applied to the part of the tube containing the chloride, to drive off any free hydrochloric acid which might have been formed by the action of the air upon it. A small porcelain boat, containing sodium, is now introduced at the other extremity of the glass tube, which is then again closed; and when the sodium is fused, the chloride is sufficiently heated to cause its vapour to come into free contact with it. A powerful reaction ensues, with the evolution of much heat, and this continues as long as any undecomposed sodium remains to act on the passing vapour. The mass in the boat, which is now a mixture of the double chloride of aluminum and sodium, in which small globules of the newly reduced metal are suspended, is allowed to cool in the hydrogen; after which it is treated with water, to remove the soluble double chloride. The residuum, consisting of small globules of aluminum, is, lastly, reduced to a solid button or mass, by fusion, at a strong heat, under a layer of the fused double chloride of aluminum and sodium.

On a large scale two cast-iron cylinders are employed, instead of the glass or porcelain tube just referred to; the anterior one of which contains the chloride of aluminum, and the posterior one a tray holding the sodium, of which 10 or 12 lbs. are commonly operated on at once. These cylinders are united by means of a smaller intermediate one, filled with clean scraps of iron, which serve to separate iron, free hydrochloric acid, and chloride of sulphur, from the vapour of the chloride of aluminum, as it passes through them. During the passage of the vapour of the chloride this smaller cylinder, or tube, is kept heated to from 400° to 600° Fahr.; but the two other cylinders are only very gently heated, since the chloride is volatilised at a comparatively low temperature, and the reaction between it and the fused sodium, when once commenced, usually generates sufficient heat for the completion of the process.

Occasionally a mixture of the double chloride of aluminum and sodium, 40 parts; chloride of sodium 20 parts; fluor spar, 20 parts; each separately dried, powdered, and then blended together; sodium, in small pieces, 7⁄2 to 8 parts, are used instead of the last.

It is likewise made from a mixture of cryolite and fused chloride of potassium, of each, in powder, 5 parts; sodium, 2 parts; a cast-iron crucible being employed; the resulting minute globules being collected and fused to a button under a layer of the double chloride of aluminum and sodium.

Prop., &c. Aluminum, when quite pure, closely approaches silver in appearance, except in being rather less white and lustrous than that metal. Ordinary specimens, called pure, have a slight bluish tint or tin-white colour, with a perfect lustre, but far inferior to that of pure silver. Sp. gr. 2·56, which by hammering may be raised to 2·67. It is both ductile and malleable; fuses at a temperature between the melting-points of zinc and silver; is not affected by either damp or dry air, or by oxygen at ordinary temperatures, or by water whether cold or boiling; even steam, at a red heat, is only slowly decomposed by it. It is not acted on by nitric acid, however concentrated, unless boiling, and then very slowly; nor by dilute sulphuric acid, sulphuretted hydrogen, and the sulphides, or even the fused hydrates of the alkalies. It is, however, readily dissolved by hydrochloric acid, with the evolution of hydrogen, even in the cold; and by a concentrated mixture of nitric and sulphuric acid. It is feebly magnetic, conducts electricity about eight times better than iron, and is more electro-negative than zinc. Commercial specimens, owing to the presence of iron and silicon, and often zinc, usually slowly tarnish in damp air, and possess the other properties described above in a somewhat diminished degree.

In a finely divided state, particularly in the state of powder or minute scales in which it was originally obtained, when heated to redness, it catches fire and burns with great rapidity in the air, and in oxygen gas with intense brilliancy, the product in each case being alumina.

Aluminum unites with the other metals, forming ALLOYS, of which some promise to be of great value in the arts. An alloy of 100 parts of aluminum with 5 parts of silver may be worked like the pure metal, but is harder and susceptible of a finer polish, whilst its property of not being affected by sulphuretted hydrogen and acids remains unimpaired; even 3% of silver is said to be sufficient to impart to it the full brilliance and colour of pure silver. An alloy containing 10% of gold is softer and scarcely so malleable as the pure metal. With 8% of iron, or 10% of copper, it still remains tough and malleable; but a larger proportion of either of these metals renders it brittle.

The presence of 2 or 3% of zinc destroys its ductility and malleability, and also impairs its colour and lustre; whilst less than even ⁄4% of bismuth renders it brittle in a high degree. Small quantities of aluminum added to other metals change their properties in a very remarkable manner. Thus, copper alloyed with 10%; of aluminum has the colour and brilliancy of gold, is harder than bronze, very malleable, and may be worked at high temperatures easier than the best varieties of iron; and with 20% is quite white, and closely resembles silver. With more than 12% of aluminum the alloy is harder, but brittle. The alloy formed of 100 parts of silver with 5 parts of aluminum is as hard as the silver of our coinage, whilst the other properties of the latter metal remain unaltered.

Uses. The valuable properties of aluminum adapt it to numerous applications in the arts and everyday life. Hitherto these have been very limited, owing to its comparatively high price; which, notwithstanding it has fallen considerably, is still sufficient to prevent its general or even extensive application. The ‘eagles’ of the French army have been made of it, as well as certain articles of jewelry, plate, &c., as brooches, bracelets, chains, spoons, and other ornamental and useful objects. Owing to its low sp. gr., it has been used as a suitable material for the minute decimal weights of chemists, for military helmets, trumpets, &c. A few cornet-à-pistons, for which its lightness and sonorousness admirably adapt it, have actually been made of it. Its power of resisting oxygen, sulphuretted hydrogen, moisture, &c., would render it invaluable as a coating to metals, particularly iron and lead, to protect them from rust or corrosion, did not its price intervene. As an internal coating for water-pipes, cisterns, &c., no other substance, except gold and platinum, is so well adapted. In chemistry, capsules, tubes, &c., either made of or coated with it, may be often advantageously substituted for those of platinum.

In addition to what has been said above, it may be observed that, in preparing aluminum, the chief care should be to avoid accidents or failure by the employment of too high a temperature, and to avoid the product being contaminated with other metals or with carbon. To ensure the purity of the metal is a matter of the greatest difficulty, owing to the facility with which foreign matters are taken up, during the process, from the materials of which the apparatus is composed; and from the substances from which it is prepared being seldom absolutely pure. Indeed, it is not too much to assert that chemically pure aluminum has not yet been obtained; and that even a very close approximation to it is of very rare occurrence. Whenever a copper boat is used to hold the sodium, the product is always contaminated with copper. Chloride of aluminum always contains some of the chlorides of iron and silicon, both of which are volatile, and probably takes up a further portion from the porcelain or earthenware used to form the apparatus. Sodium also is seldom uncontaminated with carbon or some compound of it; in which case, and likewise when it is not carefully freed from the naphtha in which it has been preserved, the product always contains carbon. The crucible, whether of porcelain or iron, in which the final fusion is made, also contributes to contaminate the metal. Hence the inferior whiteness and brilliancy of commercial specimens of aluminum; a metal which, in its absolutely pure state, may be reasonably inferred to be as superior in the above respects to silver as silver is to tin. Commercial aluminum contains from 88 to 94 per cent. only of pure aluminum, and from 1 to 4 per cent. of iron, ⁄2 to 3 per cent. of silicon, and from 1 to 6 per cent. of copper.

Aluminum salts are generally colourless, soluble, and crystallise with difficulty, and are distinguished as follows:—

Tests.—1. Ammonia and the alkaline carbonates throw down a bulky white precipitate (hydrate of aluminum) from solutions of its salts, which is insoluble in excess of the precipitant.—2. Pure potassa and soda throw down white gelatinous precipitates, freely soluble in excess of the precipitant; from which the hydrate of aluminum is reprecipitated by chloride of ammonium, even in the cold:—3. Phosphate of ammonium gives a white precipitate—4. Iodide of potassium produces a white precipitate, passing into a permanent yellow:—5. Sulphuretted hydrogen gives no precipitate:—6. Sulphydrate of ammonium precipitates alumina from these solutions:—7. Bisulphate of potassium, added to concentrated solutions, gives a precipitate of octahedral crystals of alum:—8. At a red heat its salts part with some of their acid; at a white heat, most of it, if not all:—9. Aluminum compounds, ignited on charcoal before the blowpipe, and afterwards moistened with a solution of nitrate of cobalt and again strongly ignited, give an unfused mass, which, on cooling, appears blue by day, and violet by candlelight; a test, however, which is inapplicable to fusible compounds of aluminum, and such as are not free, or nearly free, from other oxides.

Aluminum, Acetate of. Syn. Acetate of Alumina. Prep. Pure hydrate of aluminum is digested, to saturation, in strong acetic acid, in the cold; and the resulting solution, after being filtered or decanted, is either evaporated by a very gentle heat to a gelatinous, semi-solid consistence (its usual form), or is preserved in the liquid state. By spontaneous evaporation it may be obtained in long, transparent crystals.

Red liquor. From alum, in powder, 4 parts; warm water, q. s. to dissolve; acetate of lead, in powder, 3 parts; the solution and mixture being effected by lengthened agitation in a tub or other wooden vessels, and the clear liquid, after repose for a sufficient time, decanted or drawn off from the sediment.

From alum, 2 parts; (dissolved in) warm water, q. s.; solution of pyrolignite of lime (20° Baumé), 3 parts; as before, but allowing a longer time for the subsidence of the precipitate, and taking more care in the decantation than when acetate of lead is employed.

By decomposing a solution of crude sulphate of alumina with neutral or monobasic acetate of lead.

Prop. Its characteristic property is the feeble affinity existing between its acid and base, which, when it is used as a mordant, is counterbalanced by that of the fibres of the cloth or yarn to which it is applied. In other respects it resembles the other simple salts of alumina.

Uses, &c. In dyeing and calico printing, as a mordant. In medicine, properly diluted, in chronic diarrhœa; and, mixed with syrup of poppies, in slight cases of hæmoptysis (spitting of blood). It has been employed by M. Gannal as an injection to preserve animal bodies, which it will do for years.—Dose, ⁄2 to 1 dr. daily, in divided portions, taken in thin mucilage or syrup, or in barley-water; as an injection, 10 to 20 gr., to water, 4 to 6 fl. oz., in gonorrhœa, leucorrhœa, &c.

Aluminum, Chloride of. Al2Cl6. Syn. Sesquichlo′′ride of Aluminum; Alumin′ii Chlori′di, &c., L. Prep. A thick paste made of dry precipitated alumina, lampblack, and oil, is strongly heated in a covered crucible until all the organic matter is carbonised. The residuum is transferred to a porcelain tube fixed across a furnace, one end of which is connected with another tube containing dry chloride of calcium, and the other end with a small tubulated receiver. The porcelain tube is then heated to redness, whilst chlorine, dried by passing through the chloride-of-calcium tube, is transmitted through the apparatus. In one or two hours, or as soon as the tube is choked, the whole is allowed to cool, and the newly-formed SESQUICHLORIDE collected and preserved in mineral naphtha for use.

On the large scale:—Chlorine, dried as before, is passed over a mixture of pure clay, lamp-black, and coal-tar, contained in an iron retort, similar to that used in the manufacture of coal-gas (previously ignited by means of a suitable furnace), and connected with a cool chamber accurately lined with tiles of earthenware. The vapours of the SESQUICHLORIDE condense in this chamber, as a yellowish crystalline mass, which is collected and preserved as before.

Prop., &c. It is volatile at a dull red heat; excessively greedy of moisture; and very soluble, with decomposition, hydrochloric acid and alumina being formed. Once dissolved, it cannot be again recovered. Its chief use is in the preparation of aluminum.

Obs. Although alumina, like magnesia, is freely soluble in hydrochloric acid, the sesquichloride of aluminum contained in this solution cannot be obtained in the anhydrous state, or even the solid form, by its evaporation; the chloride suffering decomposition, with the formation of hydrochloric acid, which is volatilised, and alumina, which is left behind.

Aluminum, Ni′trate of. Al2(NO3)6. Syn. Nitrate of Alumina; Alu′minæ Ni′tras, L. Prep. Similar to that of the acetate and citrate. Its concentrated acid solution deposits rhombic crystals, containing 18 equiv. of water.

Aluminum, Oxide of (Al2O3), and Hydrate of (Al2(HO)6). Syn. Alumina.

Prep. Aluminum is precipitated as a hydrate from solutions of aluminum salts on the addition of an alkali or alkaline carbonate; and this precipitate, after being thoroughly washed and dried, on ignition loses its water and becomes anhydrous. The following are the best formulæ for the purpose:—

Alum is dissolved in about 20 times its weight of distilled water, and the solution is dropped slowly into pure solution of ammonia, until the latter is nearly but not entirely saturated, when the whole is set aside for some time. The clear supernatant liquid is then decanted, and the precipitate is carefully and thoroughly washed three or four times with tepid distilled water; after which it is collected on a filter, again well washed with water, and, lastly, pressed and dried between bibulous paper, either without heat, or at a temperature not higher than 120° Fahr. The product is pure hydrate of ammonium, and is converted into anhydrous alumina by exposure to a white heat in a covered crucible. The residuum, after ignition, is pure ANHY′DROUS ALUMINA, or SESQUIOX′IDE OF ALUMIN′UM.

A solution of alum is slowly added to a solution of carbonate of ammonia, avoiding excess; and the resulting precipitate, after being washed and pressed, is dried at a heat of from 120° to 180° Fahr.

Prop., &c. A soft white powder. The hydrate is freely soluble in the acids and in solution of caustic potassa and soda (from which it is precipitable by sal ammoniac); when anhydrous (as after ignition), it is scarcely acted on by acids, and when perfectly indurated, or crystallised, it is wholly insoluble; but on ignition with alkalies, alkaline ALU′MINATES are formed, and the alumina is then readily dissolved by acids, forming salts, which are mostly colourless, non-volatile, and soluble; they have a very astringent and somewhat sweetish taste, redden litmus paper, and lose their acids by ignition. Its most remarkable, or rather useful property, is its strong affinity for the fibres of organic bodies, as cotton, flax, silk, wool, &c., which are capable of taking it from its salts; and also for organic colouring matters. Hence its great use in dyeing, and in bleaching liquids and the preparation of lakes. Hydrate of aluminum agitated or digested with liquids containing vegetable colouring matter, combines with the latter, and either entirely, or to a great extent, removes it from the solution.

Moist precipitated alumina, dried at a heat between 70° and 80°, contains above 58% of water; dried at 212° Fahr., about 32% of water.

Estim. Aluminum is weighed as oxide, after ignition. The solubility of the moist or recently precipitated hydrate in solution of ammonia enable us to separate it from the ALKALINE EARTHS which, when present, are thrown down with it.

Uses, &c. The moist hydrate is used in several processes in the arts. It is the base of cobalt-blue, the lake-pigments, &c. In medicine, it is employed as an antacid and astringent, in acidity of the stomach, cholera, diarrhœa, and dysentery; in which it is said to be superior to the other absorbent remedies. (Ficinus.) It has also been highly recommended in the vomiting and diarrhœa of infancy. (Durr; Neumann; Weese; &c.)—Dose. Children 3 to 10 gr.; adults, 5 or 6 to 20 or even 30 gr., three to six times daily, suspended in water, by mucilage or simple syrup.

Aluminum, Sil′icate of. Al2(SiO2)3. Syn. Sil′icate of Alumina. A substance which, in its hydrous form, is the chief and characteristic ingredient of common clay; and which also occurs, in combination, in several other important and abundant minerals.

Aluminum, Sul′phate of. Al2(SO4)3. Syn. Sesquisul′phate of Alumina, Neutral s. of a., Alu′minæ sul′phas, A. sesquisul′phas, L. Prep. 1. Saturate dilute sulphuric acid with hydrate of aluminum, gently evaporate, and crystallise.

2. (Crude, commercial.) By mixing clay and oil of vitriol, in the way described under Alum. The product is the ‘concentrated Alum’ of the dyers.

Prop. Its crystals are needles and thin pearly plates; soluble in 2 parts of water; taste astringent, and somewhat sweetish; reaction acid; a full red heat expels its acid, leaving a residuum of pure alumina; with the sulphates of potassium, sodium, and ammonium, it forms alum.

Uses, &c. In the arts, chiefly as a substitute for alum; the sulphate of potassium in the latter, being found to be an unnecessary and costly ingredient, only useful to purify the salt from iron, by forming a compound of easy crystallisation; an object that may be effected with greater certainty by cheaper methods. In medicine, as a wash for foul and ill-conditioned ulcers; and as an astringent and antiseptic injection. M. Gannal has successfully employed a solution of this salt to preserve animal bodies, by throwing it into the arteries. Even an enema of 1 quart of it, or an injection of a like quantity into the œsophagus, will suffice to preserve a body for several weeks. The mineral called Al′unite or Alu′minite, found near Newhaven (Sussex), is a native subsulphate or basic sulphate (DISUL′PHATE) of alumina.

Aluminum, Sulphide of. Al2S3. Syn. Sul′phide of Aluminium, &c. A substance best obtained by passing the vapour of bisulphide of carbon over pure alumina, at a bright red heat. It is instantly decomposed by water, with the evolution of sulphuretted hydrogen. See Aluminum (above).

Aluminum Tann′ate. Syn. Tannate of Alumina, Eng.; Alu′minæ tann′as, L. Prep. Take of pure hydrate of aluminum (dried at 90° Fahr.), 1 part; tannic acid (dried at 212°), 2 parts; triturate them together for some time, adding just sufficient water to bring them to the consistence of a syrup, and carefully evaporate to dryness at a heat not higher than 120° Fahr.; lastly, reduce the residuum to powder.

Uses, &c. A combination of certain constitution, which is said to have been found very useful in obstinate vomiting and diarrhœa, in dysentery, and particularly in hæmoptysis, hæmorrhage, &c.—Dose, 3 to 12 or 15 gr.

Aluminium Bronze. See Bronze Aluminium.

AL′VINE (-vĭn). Syn. Alvi′nus, L.: Alvin, Fr. Of or from the belly or intestines; relating to the intestinal secretions.

AMABELE. Consists of crushed millets. See Millet.

AM′ADOU (-ăh-dōō). Syn. German tinder, Touch′wood, Pyrotech′nic sponge, Spunk‡§, Surgeon’s Ag′aric, A. of the oak, &c.; Agar′icus quer′cûs, A. quer′nus, A. Chirurgo′′rum, Fun′gus quer′cûs, &c., L.; Amadou, Agaric Amadouvier, Fr.; Zunderschwamm. Ger. A soft, spongy, combustible substance, being the prepared flesh of bole′tus fomenta′′rius (Linn.), an indigenous species of fungus found on the oak, birch, and a few other trees (REAL AMADOU or OAK-AGARIC); for which b. ignia′′rius (Linn.), a like fungus, found on the willow, cherry, plum, and other trees, is frequently substituted.

Collec., Prep., &c. The outer bark of the fungus (collected in Aug. or Sept.) having been removed with a knife, the inner spongy substance is carefully separated from the woody portion lying below, and after being cut into slices, is well beaten with a mallet until sufficiently soft and pliable. Sometimes it is first boiled in water, in order to separate the epidermis and porous parts, and to free it from soluble matter; after which it is beaten as before. In this state it is used in surgery, &c. To complete its manufacture for TINDER, it is soaked once, or oftener, in a strong solution of saltpetre (RED AMADOU; BROWN A.); or in a thin paste made of gunpowder and water, which is thoroughly forced into the pores (BLACK A.); after which it is dried, and well rubbed to free it from loose matter. The first is the more cleanly; the last the more combustible.

Uses, &c. A light brown or reddish-brown substance. In surgery, pharmacy, &c., it is used to stop local bleeding, to spread plasters on, as a compress, and for other like purposes. When covered with resin-plaster it forms an excellent article for the protection of abraded surfaces. A small piece thus prepared, of a circular shape, having a round hole cut in the middle, the size of the apex of the corn, is one of the very best corn-plasters known; as from its great softness it at once protects the part from pressure, and removes the cause. As a material for shoe-socks it is superior to all other substances. The amadou for surgical purposes must not contain nitre.

AMAL′GAM. [Eng., Ger.] Syn. Amal′gama, L.; Amalgame, Fr. In chemistry and metallurgy, an alloy containing quicksilver; more particularly one in which that metal plays a conspicuous part. Medallists improperly apply this term to all soft alloys.

Mercury unites with many of the metals by mere contact; and with some of them, as gold, silver, tin, and lead, in certain proportions, without losing its fluidity. In a few cases, as with potassium, this union is attended with considerable violence, and with the production of light and heat.

Prep. Most of these compounds may be formed by agitating or rubbing the mercury with the other metal, or metals, in the state of filings or small fragments, either with or without heat; or with the easily fusible metals, by adding it to them in the melted state; care been taken, in both cases, that the heat be not sufficient to volatilise the mercury.

Prop., Uses, &c. Some amalgams are solid, and not unfrequently crystalline; others are fluid. Of the latter several crystallise after a time, becoming solid; being, probably, merely solutions of the solid amalgams in excess of mercury. The amalgams of gold, silver, tin, zinc, &c., are extensively employed in gilding, silvering and dentistry, and in other useful arts and manufactures.

Amalgam, Ammonium. An unstable compound produced when a globule of mercury is placed in a small cavity formed in a piece of sal ammoniac, and the negative pole of a powerful galvanic battery is brought into contact with the metal, and the positive pole, with the ammoniacal salt. In a few seconds the new compound (ammonium amalgam) of the consistence of butter is formed. On withdrawing the influence of the battery, the whole returns to its former condition. By putting an amalgam of sodium into the moistened cavity of the sal ammoniac, similar results are obtained. The phenomena attending the formation of this new substance have been urged as evidence of the existence of the theoretical basic radicle AMMONIUM.

Amalgam, Elec′trical. Prep. 1. Take zinc and grain-tin, of each, 1 oz.; melt them in an iron ladle, remove it from the fire, and add of mercury (hot), 3 oz.; stir the whole well together with an iron rod, pour it into a well-chalked wooden box, and agitate it violently until cold; or, instead of this, it may be briskly stirred until cold, and then powdered. It should be preserved in a corked glass bottle.

2. (La Baumé.) Zinc, 2 oz.; grain-tin, 1 oz.; bees’ wax, ⁄2 oz.; melt, add of mercury, 6 oz., and otherwise proceed as before. Preferred by some to all other mixtures.

3. Zinc, 2 oz.; mercury, 5 oz.

Use. To cover the cushions of electrical machines. A little of the powder is poured on a piece of paper, crushed smooth with a flat knife, and then spread thinly on the surface of the cushion or rubber, previously slightly smeared with tallow; or the powder may be rubbed down with a little tallow, prior to the application of it.

Amalgam, Gild′ing. Syn. Amalgam of gold.

Prep. Take of grain-gold, 1 part; mercury, 8 parts; put them into a small iron saucepan, or ladle, and apply a gentle heat, using a smooth piece of iron as a stirrer; when the solution or combination is complete, pour it out on a clean plate or smooth stone slab.

Use. To gild brass, copper, &c., in the common process of wash or fire-gilding. A less proportion of gold than the above is used when a thin and cheap gilding is required; as by increasing the quantity of the mercury the same weight of the precious metal may be extended over a much larger surface.

Amalgam, Sil′vering.—a. For METALS. Syn. Amalgam of silver. Prep., Uses, &c. As the last, but substituting silver for gold.