C *99 3 



procured ; the produ&s yielded from the ores by 

 Fufion ; the fluxes added to promote fufion, or the 

 fubftances to prevent volatilization, and whatever 

 is fubfervient towards refining of metals or regu- 

 lufes; with the ftruftures and materials of the 

 ovens, the fuel and quantities of it employed > 

 the time for each operation, and the prepara- 

 tory cautions, including the picking, pounding, 

 wafhing, fifting, and uftulating of the ores ; and 

 drawings of the various machines and tools ufed 

 For each purpofe. 



4. The places from whence the various gems 

 or precious (tones are procured, with their prices 

 on the fpot ; the ground and ftrata wherein they 

 are found, and the figure or form of each kind 

 before being cut, whether determinate and gene- 

 ral, or accidental. 



5. The manner of manufacturing thofe im- 

 menfe quantities of faltpetre annually exported 

 from the Eaft Indies; the foil employed for the 

 lixivium, and the manner of preparing the fotf. 

 Are any animal or inflammable fubftances added 

 to it? By what means is lixivium precipitated? 

 Is an alkali ufed for that purpoie, and how is the 

 lalkali procured? Is any ufe made of the remain- 

 der of the lixivium after the precipitation of the 

 faltpetre ? Is the lixivium boiled, and infpiflated 

 by fire for the crystallization, or by the heat of 

 the fun ? 



6. If borax be artificial, in what manner and 

 from what fubftances is it made ? If native* ia 

 what ftrata and foil does it lie ? 



7. How far has the knowledge, value, and ufe 

 of metals extended amongft nations ? 



SECT. 



