108 J. P. Cooke—Atomic Weight of Antimony. 
We prepared the bromide of antimony by adding in small 
— at a time the pulverized metal to a strong solution of 
romine in sulphide of carbon. The retort containing the so- 
water bath; and then, replacing the water bath with a gas 
delicate tests which we possess for all three of these elements so 
frequently associated with commercial antimony and bromine, 
failed to show the least trace of either in the bromide of anti- 
mony we analyz The determinations of bromine were 
made in all respects like those of chlorine. Great care was 
taken not to add more than a very slight excess of argentic 
nitrate, and we found that under these conditions the superna- 
tant liquid cleared more readily above the precipitate in the 
case of bromide of silver than with the corresponding chloride, 
and for this reason the first could be washed more quickly than 
the last. The results of these determinations are embodied in 
the table on the following page. 
Here, as before, the letters indicate different preparations: @ 
was made and purified as described above; 6 was the same ma- 
terial as a redistilled and again crystallized from bisulphide of 
carbon; c was another portion of the same material several 
times redistilled and twice recrystallized from the same sol- 
vent; d was a separate preparation from the start; e was 
another separate preparation purified with extreme care. In 
the last case there was over a kilogram of the crude pro- 
duct, which was reduced by the fractional distillation and crys- 
tallization—each process repeated from ten to twenty times— 
