Mercury: 309 



they have a fpar-like appearance, and are ei- 

 ther bright and white, or yellow or black, 

 mixed with cinnabar in a ftony matrix ; thefe 

 well mixed with j. of their weight of veget- 

 able alkali, afforded him cubic and o&agonal 

 cryftals, that is, fait of filvius and tartar 

 vitriol. Phil. Tranf. 1776. The marine fait 

 of mercury is in the ftate of fublimate cor- 

 rofive. 



6. Mr. Bergman's ingenious and truly fci- 

 entific method of difcovering the proportion 

 of thefe falts is nearly as follows : Firft, by 

 trituration and cligeftion in marine acid he 

 expells the vitriolic, the mercury uniting 

 preferably with the former of thefe acids; 

 the whole is then diffblved in a fufficient 

 quantity of hot water ; into this folution he 

 drops that of marine barofelenite until no fur- 

 ther precipitation is perceived ; the true or 

 vitriolic barofelenite thus formed, being warn- 

 ed and dried, contains 13 per cent, of real 

 vitriolic acid : now vitriol of mercury con- 

 tains 19 per cent, of real acid. Hence the 

 weight of the former being found, that of 

 the latter will eafily be known ; forfuppofing 

 the weight of the barofelenite to be i oo gr. 

 then it will contain 1 3 of vitriolic acid ; and 

 fmce 19 of vitriolic acid go to 100 gr. of vi- 

 triol of mercury, 13 will go to 68,4; then 

 if the weight of the vitriol of mercufy be 

 X 3 fubtrafled 



