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AMERICAN NATURALIST. 
Vol. IV. —OCTOBER, 1870. — No. 8. 
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RECENT ADVANCES IN GEOLOGY.* 
BY J. W. FOSTER, LL. D. 
Mr. President, and Gentlemen of the American Association 
for the Advancement of Science: — 
THERE is an article contained in our Constitution which 
requires the retiring President to address the Association 
in general meeting ; and custom has prescribed that he select 
for his theme some new and important discoveries in science, 
or some new inventions and processes in the arts. ; 
It is in the discharge of this duty that I appear before you 
on this occasion, and solicit your attention for the passing 
hour. So vastis the domain of science, and so numerous 
have become its cultivators in almost every part of the 
world, that, even if I had the capacity, the labor of embody- 
ing the results of a single year, in a brief address, would be 
a mere accumulation of details devoid of that spirit which 
gives them value— generalization. 
I shall, therefore, restrict myself to the researches which 
have been made in those departments of science which with 
me have been the subjects of special investigation ; and shall 
* Address of the retiring president of the American Association for the Advance- 
ment of Science, J. W. Foster, LL. D., delivered at Troy, New York, on the evening of 
August 18, 1870. 
ZO he the P. " g fn & 
Entered accordi 
AMER. NATURALIST, VOL. IV. 57 (449) 
