2 
reflecting its image from the upper surface of the compound 
prism, the lines in the spectrum under examination may be 
readily registered. 
Dr. J. S. Newberry read a paper 
ON THE EARLIEST T'RACES OF MAN FOUND IN 
NortH AMERICA. 
Dr. Newberry stated that the human relics for which the 
highest antiquity had been claimed were the Natchez bone 
and Table Mountain (California) skull. If it could be shown 
beyond question, that these bones really. ocgurred in the 
positions to which they had been referred, we should have 
evidence that man existed on this continent as a contempo- 
rary with the mammoth, mastodon and other extinct mam- 
mals, and at a period so remote that all the topographical 
features of the surface have since changed—in the case of 
Table Mountain the bottom of a valley having become a 
mountain summit. As regards the Natchez bone, geological 
changes have been effected since the date assigned it, which, 
mm Sir Charles Lyell’s judgment, must have required a hun- 
dred thousand years. In neither of these instances, were the 
human remains actually found by credible persons in strata 
of high antiquity, and no dependence whatever can be placed 
upon inferences made from this material in the solution of 
the question of the antiquity of man. We may to-morrow 
obtain indubitable evidence of the occurrence of the remains 
of man in the Table Mountain tertiaries and the Vicksburg 
bluff; but until such evidence be discovered we must discuss 
the question, leaving these hypothetical cases entirely out of 
view. No solid and enduring scientific fabric can be reared 
on doubtful premises. 
The caves of our country have as yet scarcely been entered 
upon as ground for archzeological research. But one cavern 
has been examined with any care—that of Carlisle, Pa., by 
Professor Baird—and this may be said to have been but par- 
tially explored. Human remains were found in it, but not of 
special interest. The fauna represented’ by the great number 
