P. Collier—Remarkable Nugget of Platinum. 128 
at the last semi-revolution of the earth’s equinoxes about 
10,000 years ago. If we are to look for marks of glaciation in 
the earlier and more extreme period of the eccentricity of the 
earth's orbit we should go farther south. The glacial detritus 
in California, where Prof. Whitney has found human remains, 
may belong to that earlier period. But it is evident that the 
glacial phenomena of New England are comparatively recent in 
their origin. 
Art. XIV.—A Remarkable Nugget of Platinum; by PETER 
CoLuigER, of Washington, D. C. 
SEVERAL years ago I came into possession of a nugget of 
platinum, said to have been found upon land adjacent to the 
village of Plattsburgh, New York. Upon examination, the 
hugget was found to be composed entirely of native platinum 
and chromite disseminated through it. is chromite was 
black and of a somewhat resinous luster. The dimensions of 
of only ‘74 per cent. The chromite was decomposed by 
fusion with bisulphate of potassium. Its composition is given 
as follows: 
