Point VIII

It is convenient for Clock-makers, or Watch-makers, if a Water be destilled from it, which soldereth Iron or Steel, without fire, if a drop of that Aqua-fortis be dropped upon it, whence the Iron growing hot, it presently waxeth soft, as if it had been soldered in the fire by the help of Copper.

If an Aqua-fortis be destilled from Niter and calcined Vitriol (NB. that there must be no Water or Phlegm in the Spirit) and two little pieces of Iron be melted with it, (between which there must be little Filings of Iron) then the Iron groweth hot by the Aqua-fortis, which acteth upon it, and the one will be joined to the other by melting, as if it had been done by the fire. But he that will use that water, must know how to prepare it himself, because such is no where to be found to sell.