J. P. Cooke—Atomic Weight of Antimony. 383 
and 120°3 for the six determinations in which we placed most 
confidence. The antimonious bromide used in these determi- 
nations was purified first by fractional distillation, and secondly 
by crystallization from a solution in sulphide of carbon. In 
the crystallized product thus obtained, the bromine was deter- 
mined gravimetrically as bromide of silver in the usual way. 
Although it seemed at the time that the results were as accord- 
knowledge of the relations involved as will enable us to obtain 
at once more sharp and decisive results than are now possible.” 
Unfortunately this investigation has been delayed by causes 
beyond our control. 
n 
which we deyised for subliming iodide of antimony; and in a 
the preparation. The fine acicular crystals are ear color- 
the small differences between the results previously obtained 
arose wholly from the analytical process, and not from any 
want of constancy in the material analyzed; and further that 
these sources of error are to a very great extent under control. 
Moreover, we have found that the volumetric determination of 
Tomine by silver was not materially affected, if at all, by the 
