352 



PROCEEDINGS OP THE AMERICAN ACADEMY. 



This conclusion concerning the action of the substances on mercurous 

 chloride is reinforced by the facts concerning the extent to which mer- 

 curic chloride is dissolved by solutions of various chlorides. Solutions of 

 sodic chloride dissolve amounts of mercuric chloride which increase with 

 the amounts of common salt present, until the saturation point is reached, 

 while solutions of hydrochloric acid dissolve a maximum of mercuric 

 chloride at a concentration of acid of seven times normal, remaining 

 almost constant in action upon further concentration.* 



The parallelism between the tendency of these soluble chlorides to dis- 

 solve mercuric chloride on the one hand, and their tendency to decompose 

 mercurous chloride on the other hand, is thus rather striking. 



In addition to the four chlorides given iu the tables, cadmic chloride 

 was used in a special series of experiments. The solution after digestion 

 with calomel was analyzed by immersing in it a roll of clean copper 

 gauze, which was dried and weighed, and then ignited in hydrogen and 

 weighed again. Preliminary experiments showed this to be a convenient 

 and sufficiently accurate method of determining mercury in the presence 

 of cadmium. 



Although solutions of 2, 4, and 8 times normal were used, in no case 



Mercuric Chloride fodnd in Solutions of Baric Chloride. 



No. of 

 Exp. 



(a 



h 

 (a 



Wt. of 



Solution 



taken. 



grm. 

 10G.5 



112.0 



101.8 



120.3 



94.5 



112.8 



131.2 



10G.8 



Vol. 



of 



Solution. 



c. c. 



97.8 

 103.0 



89.8 

 100.1 



80.2 



95.7 

 103.8 



84.5 



wt. of 



HgS 



found. 



m.g. 

 3.6 



3.9 

 6.7 



8.0 



8.8 

 20.5 

 16.7 



wt. of 

 ilgCU in 

 1 Litre of 

 Solution. 



grm. 



0.013 : 



1000 



c 



Milligrams 



HgOlj for 



every i Mol. 



BaClo. 



44.0 



58.G(?; 



53.5 



<7.0 



* Homeyer and Ritsert, Pharm. Ztg., 33, 738, quoted by Comey, Diet, of Solubili- 

 ties, 227 (1896). 



Ditte, Ann. Chim. phys., (5) 22, 551 ; Engel., ibid. (6), 17, 362. See Comey, as 

 above. 



