VOL. LXXIII.] PHILOSOPHICAL TRANSACTIONS. 32Q 



'Copper- in the vitriolic acid. — 100 grs. of copper require nearly 183 grs. real 

 vitriolic acid for their solution. The proportion of acid to that of water being 

 as 1 to 4-, or at least as 1 to -jV, and a strong heat must also be applied. The 

 dephlogistication of 128 grs. of copper, treated in this manner, affords 11 cubic 

 inches of inflammable air, and nearly 65 of vitriolic air. 1 00 grs. of vitriol of copper 

 contain 27 of copper, 30 of acid, and 43 of water, of which it loses about 28 

 by evaporation or slight calcination. The solution of lOOgrs. of copper affords 

 373 of blue vitriol. 



Copper in nitrons acid. — 100 grs. of copper require 130 of real nitrous acid 

 to dissolve them. If the acid be so far diluted as that its proportioirto that of 

 water be as 1 to 14, the assistance of heat will be necessary, otherwise not. 

 This solution affords 674 cubic inches of nitrous air. The calces of copper 

 are also soluble in this acid. 



Copper in marine acid. — 100 grs. of copper require llQOgrs. of real marine 

 acid to dissolve them, and also the assistance of a moderate heat, the proportion 

 of acid to that of water being as 1 to 4-l, that is, its specific gravity being 1.186, 

 if a greater heat be used, more of the acid will be requisite, as much will be 

 dissipated. If the acid be more concentrated, it will act more vigorously. 

 The calces of copper are also soluble in this acid, though not so easilv as in the 

 nitrous acid. < 



Tin in the vitriolic acid. — 100 grs. of tin require for their perfect solution 872 

 grs. of real vitriolic acid, whose proportion to water should not be less than as 1 

 to -fL-, and also the assistance of a strong heat ; when the action of the acid has 

 ceased, some hot water should be added to the turbid solution, and the whole 

 again heated. This solution affords 70 cubic inches of inflammable air. Tin is 

 also soluble in a more dilute acid, but not in so great quantity. The calces of 

 tin (except that precipitated from marine acid by fixed alkalis) are insoluble in 

 this acid. 



Tin in the nitrous acid. — 100 grs. of tin require, for their perfect solution, 

 1200 grs. of real nitrous acid, whose proportion to water should be at least as 1 

 to 25, and the heat not exceeding 60°: the quantity of air afforded by such 

 solution is only 10 cubic inches, and it is not nitrous. The solution is not per- 

 manent; for in a few days it deposits a whitish calx, and if the weather be warm 

 bursts the phial. The calces of tin are insoluble in this acid. 



Tin in the marine acid. — 100 grs. of tin require, for their solution, 413 

 of real marine acid, whose proportion to water is as 1 to 4-i-, and also the 

 assistance of a moderate heat. This solution affords about 90 cubic inches of 

 inflammable air and 10 of marine air. The calces of tin are nearly insoluble in 

 this acid. 



Lead in the vitriolic acid. — 100 grs. of lead require, for their solution, 600 

 vol. xv. U u 



