64 PROCEEDINGS OF THE AMERICAN ACADEMY 



by the COg gas into the colder portion of the combustion-tube, the 

 greater part at least of the sublimed oxide would be retained in the 

 small tube, which was of course at each stage weighed with the nacelle 

 as at first. Our results were as follows : — 



Weight of SbOCl 0.4939 grammes. 



Loss at 280'' 0.1271 „ 



Required by theory of reaction 1, if Sb= 120 0.1305 „ 



Total loss at red heat; that is, in both stages . 0.2179 „ 

 Required by theory of reactions 1 and 2 . . 0.2174 „ 



It was evident from this determination that the order of the decom- 

 position was precisely that indicated by our reactions, although the 

 end of the first stage was not quite so sharply marked as the end of 

 the second ; and this would naturally be expected. 



As the residues obtained on distilling chloride of antimony showed, 

 when further heated, precisely the same order of phenomena which we 

 have just described, and when heated to redness yielded the same 

 crystals of oxide of antimony as before, it was plain that the residue 

 left on evaporating the chloride at a temperature not exceeding 120*^ 

 was chiefly at least SbOCl ; but that this when heated more intensely 

 was converted into Sb405Cl2 before the temperature reached 280°, and 

 finally at a red heat was converted wholly into SbjOg. We therefore 

 endeavored to determine the amount of oxichloride in one of our prep- 

 arations of chloride of antimony by distilling a weighed amount from a 

 platinum nacelle at as low a temperature as possible in a current of dry 

 carbonic acid, and heating the residue to a temperature of about 275'^. 

 We thus obtained the following results : — 



In order to yield 0.146 % of oxygen, which would reduce the per 

 cent of chlorine in the preparation from 47.020 to 46.608, as in the 

 scheme on page 62, there would be required 1.155 % of Sb^O^Clg. 



Although the results of the above detern;inations accord within a 

 few per cent of the quantity estimated, yet it was perfectly clear dur- 



