446 



BOOK X. 



A — Ampullae arranged in the vessels. B — An ampulla standing upright between 

 IRON RODS. C — Ampullae placed in the sand which is contained in a box, the 

 spouts of which reach from the opercula into ampullae placed under them. 

 D — Ampullae likewise placed in sand which is contained in a box, of which the 

 SPOUT from the opercula extends crosswise into ampullae placed under them. 

 E — Other ampullae receiving the distilled aqua and likewise arranged in sand 

 contained in the lower boxes. F — Iron tripod, in which the ampulla is usually 

 placed when there are not many particles of gold to be parted from the silver. 



G — Vessel. 



rises into the operculum, there is put into the ampulla one lozenge or two ; 

 these are made of soap, cut into small pieces and mixed together with 

 powdered argol, and then heated in a pot over a gentle fire ; or else the 

 contents are stirred with a hazel twig split at the bottom, and in both cases 

 the aqua effervesces, and soon after again settles. When the powerful vapour 

 appears, the aqua gives off a kind of oil, and the operculum becomes red. But, 

 lest the vapours should escape from the ampulla and the operculum in that 

 part where their mouths communicate, they are entirely sealed all round. 

 The aqua is boiled continually over a fiercer fire, and enough charcoal must be 

 put into the furnace so that the live coals touch the vessel. The ampulla is 

 taken out as soon as all the aqua has been distilled, and the silver, which is dried 

 by the heat of the fire, alone remains in it ; the sUver is shaken out and put 

 in an earthenware crucible, and heated until it melts. The molten glass is 

 extracted with an iron rod curved at the lower end, and the silver is made 



