J. L. Smith on the Cohahuila Meteoric Irons. 385 
eteor, and all confirm me in the opinion that the autumn of 
1837 is about the time of its fall. My party were in consider- 
able danger while in the mountains, as we were encamped two 
miles from the regular trail, when some 300 Indians went through 
with a large number of their stolen horses.” 
Whether or not the time above specified is that of the fall 
of one or more of these irons, is a matter of little moment ; 
the probabilities are, however, strongly in favor of it ; never- 
theless, it forms one of the most interesting groupings of me- 
teoric irons known in any part of the world ; especially, as the 
Masses are solid and compact masses, and not fragile and half 
stony, as the Atacama iron, that may have been broken artifi- 
cially after its fall, and the fragments scattered by Indians and 
explorers in search of silver. Each one of these masses merits 
# Separate examination, which I hope to be able to give, sooner 
or later, to satisfy my mind on one or two points connected 
with their common physical structure and chemical composi 
tion. But I will not delay this paper until then. : 
Six of’ these masses have been brought to this country, weigh- 
§ Tespectively 290, 430, 438, 550, 580 and 654 lbs. They 
are irregular compact masses, without any evidence of stony 
minerals, They belong to the softer irons, not very difficult to 
cut with the saw ; as yet there has been but about one ounce 
detached from one of the masses, which has enabled me to 
make out the following description : 
Specific gravity 7-692. It contains— 
ied 92°95 
Nickel, 6°62 
Cobalt, 48 
Phosphorus, 02 
1s aca, very minute quantity. 
This composition differs somewhat from the meteoric iron 
called Santa Rosa; but since examining that I have reason 
to believe that the quantity of nickel given is too small, some 
portion of it having remained with the iron; it being far 
More difficult than is usually supposed to separate accurately 
Minute quantities of nickel from iron. Future examinations 
May prove that the Santa Rosa belongs to the group of irons 
der notice, 
