J. L. Smith—Coneretions in Meteoric Irons. 493 
tion is obtained, composed of €r -010, Co ‘015, Fe,O, ‘028; in 
fact it is daubréelite with cobalt and oxide of iron coming from 
an unknown cobalt compound that had made itself very mani- 
fest in a previous part of the examination, 
The residue, which has been now reduced to a few milli- 
grams, is found to be graphite with a few minute particles of a 
siliceous mineral. The only novel feature of importance in the 
results above stated is the appearance of considerable amounts 
of cobalt in certain parts of the process. It is evident that this 
IS not a part of the composition of the troilite, for chlorhydric 
acid removes this latter mineral and i 
One time in a plastic state from the effect of heat. Some may 
think otherwise from the fact that petroleum-ether dissolves 
Sulphur and sulphur carbon compounds from the concretions 
im the iron. But the fact is that my observations and experi- 
Ments on cast iron show that this objection has no weight. As 
by a proper treatment I dissolve crystals from most cast iron by 
the agency of ether or petroleam-ether—a note of which fact I 
have already publicly announced—my experiments on this 
point are both clear and convincing although I have not yet 
completed them, So far as they have gone they were shown 
€xperimentally to M. Berthelot and others, and if my health 
Permits I shall complete them before many months. 
