350 



PROCEEDINGS OP THE AMERICAN ACADEMY. 



amounts of stannous chloride gave plentiful white precipitates of 

 calomel. 



In all cases except that of cadmium, the mercuric salt in solution was 

 determined as sulphide. The black precipitate produced by hydrogen 

 sulphide was collected on a Gooch crucible, washed with alcohol, carbon 

 disulphide, and again with alcohol, and finally dried at 100°. Satis- 

 factory agreement between parallel analyses, which were almost always 

 made in duplicate, was obtained. In the tenth-normal solutions of sodic 

 chloride the amount of mercuric chloride was too small to be collected, 

 hence it was determined colorimetrically by comparison with known 

 solutions of similar dilution. 



The following table explains itself. The last-column contains an arbi- 

 trary ratio which is an index of the changing relationship between the 

 amounts of mercuric chloride formed and the amounts of sodic chloride 

 present. The values in the third column were calculated from those in 

 the second ; and the values in the fifth column from those in the third 

 and fourth. 



Mercuric Chloride found in Solutions of Sodic Chloride. 



No. of 

 Exp. 



( a 



S a 



Wt. of 



Solution 

 taken. 



grm. 



64.5 

 66.1 

 65.9 

 80.3 

 75.4 

 83.0 

 73.8 

 80.3 

 58.7 

 69.7 



Vol. 



of 



Solution. 



62.0 

 63.5 

 61.1 

 74.5 

 68.8 

 75.7 

 64.6 

 70.3 

 49.4 

 58.8 



Wt. of 



HgS 

 found. 



m.g. 



2.2 



2.3 



6.8 



8.2 



11.4 



12.6 



21.1 



22.8 



27.2 



32.5 



Wt. of 

 HgCI., in 

 1 Litre of 

 Solution. 



grm. 

 0.0041 



Mean Wt. 

 of HgClj 



in 

 1 Litre. 



grm. 

 0.0041 



0.041 



0.129 



0.194 



0.380 



0.643 



C 



Cone, of 



NaCl 



Solution 



in Equiv. 



Grams. 



equiv. 

 0.10 



1.00 



2.00 



2.50 



3.80 



5.00 



1000 - c 



Milligrams 



Hg<Jl 2 for 



every Mol. 



NaCl. 



41.0(?) 



41.5 



64.5 



.7.6 



100.0 



128.6 



