430 



BOOK IX. 



Others build a hollow vaulted chamber, of which the paved floor is made 

 concave toward the centre. Inside the thick walls of the chamber are the 

 furnaces. The doors through which the wood is put are in the outer part of the 

 same wall. They place the pots in the furnaces and fill them with crushed 

 ore, then they cement the pots and the furnaces on all sides with lute, so that 

 none of the vapour may escape from them, and there is no entrance to the 



A. ENCLOSED CHAMBER. B DOOR. C LITTLE WINDOWS. D MOUTHS THROUGH THE 

 WALLS. E FURNACE IN THE ENCLOSED CHAMBER. F POTS. 



furnaces except through their mouths. Between the dome and the paved 

 floor they arrange green trees, then they close the door and the little windows, 

 and cover them on all sides with moss and lute, so that none of the quick- 

 silver can exhale from the chamber. After the wood has been kindled the 



possible however, that it was written late in the I5th Century (see Appendix B). He describes 

 the preparation of the metal from the crude ore, both by roasting and reduction from the oxide 

 with argol and saltpetre, and also by fusing with metallic iron. While the first descrip- 

 tion of these methods is usually attributed to Valentine, it may be pointed out that in 

 the Probierbuchlein (1500) as well as in Agricola the separation of silver from iron by 

 antimony sulphide implies the same reaction, and the separation of silver and gold with 

 antimony sulphide, often attributed to Valentine, is repeatedly set out in the Probier- 

 buchlein and in De Re Metallica. Biringuccio (1540) has nothing of importance to say as to 

 the treatment of antimonial ores, but mentions it as an alloy for bell-metal, which would 

 imply the metal. 







