J. P. Cooke—Atomic Weight of Antimony. 109 
to the few grams used in the analyses.) These methods of 
ert the substance were thus pushed to their utmost 
imits. 
ANALYSES OF ANTIMONIOUS BROMIDE. 
DETEMINATION OF BROMINE. 
Wt. of SbBr, taken .Wt.of AgBr ¢ of Bromine 
in grams. obtained. 
No. Br=80, Ag 108. 
l, a. 1°8621 2°9216 66°765 
2, a. 0°9856 1°5422 66°584 
3, 5. 1:8650 2°9268 66°79 : 
4, b. 1°5330 2°4030 66°703 
5, b. 1°3689 2°1445 66°663 
6, ¢. 1°2124 1°8991 66°655 
7, ¢. 0°9417 1°4749 66°647 
8, d. 2°5404 3°9755 66°593 
9, d. 1°5269 2°3905 66°623 
10, e. 1°8604 2°9180 66°743 
11, ¢. 1°7298 2°7083 66°624 
12, ¢. 3°2838 5°1398 66°604 
13, ¢. 2°3589 3°6959 66°671 
14, €. 1°3323 2°0863 66°635 
15, ¢. 26974 4°2285 66°708 
Mean value from last six determinations, 66°664 
Mean value from all the determinations, 66°6665 
Theory Sb 120 requires, ......--------- 66°6666 
TOOTS SAPS oO eee ou ieee 66°2983 
whether we take Stas’s or Dumas’s values for the atomic 
weights of bromine and silver, the atomic weight of antimony 
deduced from the above determinations is exactly 120-00. 
_This is certainly a remarkably close confirmation of our pre- 
vious conclusion. Indeed the wonderful coincidence between 
the observed and the theoretical results must be to a certain 
extent accidental ; for no process of chemical analysis is capa- 
ble of the accuracy which this agreement would imply. Still 
table errors of the process, so 
far as they are indicated by the variations from the mean 
