332 PHILOSOPHICAL TRANSACTIONS. [ANNO 1783. 



12 cubic inches or less, if heat be not applied. Precipitate per se is much more 

 difficultly dissolved by nitrous acid than genuine mercury, which I attribute to 

 the attraction of the aerial acid contained in the precipitate. 



Mercury hi marine acid. — The marine acid, in its common phlogisticated state, 

 does not act on mercury, at least in its usual state of concentration; but 

 Mr. Homberg, in the Paris Memoirs for the year 1700, assures us, he dissolved 

 mercury in marine acid, whose specific gravity was 1.300, by keeping it some 

 months in digestion. The authors of the Cours de Chymie de Dijon affirm 

 also its solubility in this acid, though in very small quantity. The dephlogisti- 

 cated marine acid, in a vaporous state, certainly acts on it, though while in a 

 liquid state it is too weak, by reason of its dilution. Precipitate per se is also 

 soluble in marine acid, with the assistance of heat. 100 grs. of sublimate cor- 

 rosive contain 77 of mercury, l() of real acid, and 6 of water. 100 grs. of 

 mercurius dulcis contain 86 of mercury, and 14 of acid and water. 



Zinc in vitriolic acid. — 100 grs. of zinc require, for their solution, 100 grs. of 

 real acid, whose proportion to that of water may be as 1 to 8, 10, or 12, apply- 

 ing heat towards the end, when the acid is almost saturated. A small quantity 

 of black powder always remains undissolved. The product of inflammable air is 100 

 cubic inches. It is soluble in the concentrated vitriolic acid, with the aid of 

 heat. 100 grs. of vitriol of zinc contain 20 of zinc, 22 of acid, and 58 of 

 water. The calces of zinc, if not exceedingly dephlogisticated, are also soluble 

 in this acid. 



Zinc in nitrous acid. — 100 grs. of zinc require, for their solution, 125 grs. of 

 real nitrous acid, whose proportion to that of water is as 1 to 1 2, applying from 

 time to time a slight heat. If a concentrated acid be used, less will be dissolved, 

 as much of the acid will escape during the effervescence. I could procure no 

 nitrous air from the solution by any management, as the nitrous acid is in part 

 decomposed during the operation. The calces of zinc, if not too much dephlo- 

 gisticated, are also soluble in this acid. 



Zinc in marine acid. — The same quantity of zinc requires of this acid 210 

 grs. the proportion of real acid in the menstruum being as 1 to Q, and using 

 from time to time a slight heat. If a less dilute acid be used, more real acid 

 will be requisite, as much of it will escape during the effervescence. The calces 

 of zinc are also soluble in this acid. 



Bismuth in vitriolic acid. — 200 grs. of oil of vitriol, whose specific gravity 

 was 1.863, dissolved but 3 grs. of bismuth in a strong heat; but slightly dephlo- 

 gisticated a greater quantity. 400 grs. of spirit of vitriol, whose specific gravity 

 was 1.200, dissolved only 1 grain. The calces of bismuth are much more 

 soluble. The solution of the 3 grs. afforded 4 cubic inches of vitriolic air. 



Bismuth in nitrous acid. — The solution of 100 grs. of bismuth require but 



