68 PROCEEDINGS OF THE AMERICAN ACADEMY 



gas. No sublimate was formed, and only a very slight empyreumatic 

 odor could be perceived. 



Weight of platinum nacelle 6.2493 grammes. 



„ nacelle and dried precipitate . ; . 9.5273 „ 



„ portion taken 3.2780 „ 



„ nacelle and precipitate after heating 



to 285° for over half an houj; . 9.5234 „ 



Loss of weight of portion taken 0.0039 grammes. 



Corresponding loss for whole precipitate . . 0.0041 „ 

 Weight of red sulphide as above 3.4196 „ 



» gray sulphide 3.4155 



The carbonaceous residue left on dissolving this whole amount of 

 gray sulphide in hydrochloric acid was barely perceptible. It was 

 collected, however, as usual, on a weighed paper disk, and estimated. 



Weight of small paper filter 0.0198 grammes. 



„ same with residue 0.0212 „ 



„ residue 0.0014 „ 



Calculated for whole precipitate 0.0015 „ 



Weight of gray sulphide as above .... 3.4155 „ 



Total weight of gray sulphide 3.4140 „ 



Corresponding weight of antimony assumed to 



be f of the sulphide 2.4386 „ 



Per cent of antimony in the antimonious chlo- 

 ride under examination 53.374 „ 



It will be noticed that this result is practically identical with the 

 mean of the previous determinations, which, as will be seen by refer- 

 ence to the table on page 42, was 53.401 ; and, by reviewing the facts 

 stated in that connection, it will be perceived that this agreement is in 

 itself alone a strong confirmation of the conclusion which we deduced 

 from our first experiments on the synthesis of the gray sulphide of 

 antimony, — that of the two values of the atomic weight of antimony in 

 question, the lower is the more exact. 



