J. P. Cooke—Atomic Weight of Antimony. 117 
of Sb,O,. In another experiment, we used crystallized 
First stage: 5SbOCI=Sb,0,Cl,+SbCl, ; (1) 
Second stage: 3Sb,0,Cl,=5Sb,0,+2SbC1,; (2) 
larger sublimate of chloride, we varied the apparatus in our 
. third experiment so far as to place the nacelle in a tube of the 
shape represented in the accompanying figure. This tube was 
weighed with the nacelle, and was so 
selected that it quite closely fitted the — SS) 
combustion - tube within which it was S Fits, AeA ot 
placed for heating, as shown in figure b dotted lines. <And it 
is evident that, while with this arrangement the SbCl, would 
be swept by the CO, gas into the colder portion of the combuas- 
tion-tube, the greater part at least of the sublimed oxide would 
be retained in the small tube, which was of course at each stage 
wesned with the nacelle, as at first. Our results were as fol- 
Ows :— 
Weight of SbOCI.- TS UE: 04939 grams, 
Loss at 280° _.. 01271 : 
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 
ecomposition 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. 
showed, when further heated, precisely the same order of phe- 
it was plain that the residue left on evaporating the chloride at 
a temperature not exceeding 120° was chiefly at least SbOCI ; 
but that this when heated more intensely was converted into 
