46 R. H. Lee—Atomic Weights of Cobalt and Nickel. 
CoCl,. Silver. Equivalent. 
1 ( 2°352 3°9035 
2 4°210 6°990 29°54 
3 3°592 5°960 29°59 
4 | 2°492 4°1405 29°50 
5 } 4°2295 7°0255 29°51 
The mean of these five determinations is 29°54. In all cases | 
the chloride was dissolved in boiling water and the solution al- _ 
lowed to cool before precipitating with AgNO,. The argentic _ 
chloride was reduced in hydrogen. The method employed for _ 
the eke less of pure cobalt is not stat - 
* determined the atomic weights of cobalt and nickel | 
in 1863. Pure metallic cobalt was prepared by igniting chloride _ 
of purpureocobalt in hydrogen. ‘The metal was dissolved in 
nitric acid and the solution evaporated and strongly heated. — 
The black oxide obtained was ignited in a current of carbonic © 
di-oxide, by which it was converted into light brown cobaltous — 
oxide €00, which was then reduced by pure hydrogen. Omit- 7 
ting two trial experiments, the results obtained were as ‘follows: t 
€o00. Cobalt. Cobalt pr. ct. 
First sample, 1 2°1211 1°6670 78°591 
2 2°0241 15907 78°588 
3 2°1226 1°6673 _ 78°550 
4 1°9947 15678 78°598 
5 3°0628 2°4078 78614 
First ce twice purified— 
1 2°1167 16688 78°603 
2 i Sab G 1°3924 78°591 
S 17852 1°4030 78°591 
First specimen three times purified — 
1 1°6&78 1°3264 78°588 
2 2°2076 1°7350 78°592 
Mean, 78°590 
Second specimen—- 
1 2°6851 2°1104 78°597 
2 2°1461 1°6868 78°598 . 
Mean, 78°597 
Third specimen-— 
1 3°4038 2°6752 78°595 
2 2°2778 1°7901 78°589 
3 2°1837 1°7163 78°596 
Mean, 78°593 
* Annalen der Pharmacie, vol. exxvi, pp. 322-336. 
