158 J. Lawrence Smith on Meteorites. 
This mineral although not usually much dwelt upon when 
speaking of meteorites, is decidedly the most interesting one asso 
ciated with this class of bodies, even more so than the “nickolifats 
ous iron. It has no representative in genus or species among ter- 
restrial minerals, and is one possessed of highly interesting prop- 
erties. Although among terrestrial minerals phosphates are found, 
not a single phosphuret is known to exist ; so true is this (that 
' with our present knowledge) if any one thing could convince me 
more strongly than another of the non- terrestrial origin of any 
natural body, it would be the presence of this or some similar 
phosphuret. It is commonly alluded to as a residue from the ac- 
tion of hydrochloric acid upon meteoric iron, when in fact it ex- 
ists in plates and fragments of some size in almost all meteoric 
iron; and there is reason to believe that it is never absent from 
any of them in some form or other: what is meant by ‘“ some 
size” is, that it is in pieces large ey to be seen by the naked 
eye, and to be detached mechanical 
In an examination of the meteoric specimens in the Yale Col- 
lege Cabinet, more than half of them have been discovered to 
contain Schreibersite visible to the eye, that had been considered 
pyrites. Among them, the large Texas meteorite was examined, 
and although none was visible on the surface, a small fragment 
of the same mass given me by Prof. Silliman, contains a piece 0 
Schreibersite of over a grain weight. 
e reason why it has not attracted more attention, arises from 
its resemblance to pyrites; I tad fei hb state a ready manner 
of telling whether it be such or 
tach a small fragment, ata hold a magnet capable of sustain- 
ing five or six ounces or more, within half an inch or an inc 
of the fragment, if it be Schreibersite it will be attracted with 
great readiness ; the magnetic pyrites requiring a very close ap- 
proximation of the magnet before attracted. This, with some 
little experience, becomes a ready method of separating the two. 
It is not, however, to be expected that this method alone, is to 
satisfy us, when other means can be appealed to for distinguishing 
this mineral ; the following is one which is readily accomplishe 
with the smallest fragment. (half a milligramme). Melt in a small 
loop of platinum wire, a little carbonate of soda, add the small- 
est fragment of nitrate of soda and the piece of mineral, hold the 
mixture in the flame of a lamp for two or three minutes; place 
the bead of soda in a watch glass, add a little water and filter ; 
to the filtrate add a drop or two of acid to neutralize the excess 
of carbonate of soda; evaporate nearly to dryness; add a drop of 
ammonia, and then a drop of ammoniacal sulphate of magnesia, 
when the double phosphate of magnesia and ammonia will show 
self, and the crystalline form will be Séognined under the micro- 
pe. ee et 
