42 



PROCEEDINGS OP THE AMERICAN ACADEMY 



of chloride of antimony on heating the red sulphide up to the point of 

 its conversion to the gray modification. INIoreover, less tartaric acid is 

 required, — not more than 6 grammes to every gramme of chloride, — 

 and consequently less is occluded by the precipitate, so that with care 

 the carbonaceous residue can be reduced to an insignificant amount. 



The following table exhibits the results of these antimony determina- 

 tions, as well as the general result of the assumed complete analysis of 

 antimonious chloride. The per cent of chlorine taken is the mean of 

 the first thirteen determinations of the previous table, as these only 

 had been made at the time the second table was drawn up, and it there- 

 fore exhibits the results exactly as they were presented to us at this 

 stage of the investigation. 



Analysis of Antimonious Chloride. 

 Determination of Antimony. 



Sb.,Sg obtained % of Antimnnv when % of Antimony if 

 iii grammes. Sb:S = 120':32.* Sb:S = 122: 32.t 



2.8973 

 3.8417 

 3.3201 

 3.4009 

 3.6072 

 3.1958 



53.275 

 53.473 

 53.316 



53.882 

 53.593 

 53.367 



•53.525 

 53.725 

 53.567 

 53.633 

 53.845 

 53.618 



Mean of all Analyses 



53.401 



53.652 



Mean Result of Complete Analysis. 

 Antimony, the mean of six determinations 53.401 

 Chlorine, „ „ thirteen „ 46.611 1 



100.012 



53.652 

 46.611$ 



100.263 



* Or assuming that 4 of the gray sulphide is antimony, as deduced from 

 actual synthesis. 



t According to the generally accepted theory. 



t When CI = 35.5 and Ag = 108, according to Dumas. 



