416 PROCEEDINGS OF THE AMERICAN ACADEMY 



In all these experiments, the pipes employed were open at botli 

 ends. 



Now that science is in possession of this delicate optical method, 

 which requires for its success no nice musical ear, other problems, 

 heretofore settled by assumption, may be brought within the range of 

 demonstration. 



Five hundred and eighty-seventh. Meeting. 



November 13, 1867. — Statute Meeting. 



The President in the chair. 



The President announced the decease of Professor Mitter- 

 maier, of the Foreign Honorary Members. 



Professor Levering; announced that Vol. IX. Part I. of the 

 Memoirs, was ready for distribution. 



Professor Edward C. Pickering was elected a Resident Fel- 

 low in Class I. Section 3. 



Dr. C. H. F. Peters was elected an Associate Fellow in Class 

 I. Section 2. 



On the motion of Dr. G. E. Ellis, the Rumford Committee 

 was instructed to collect papers relating to the life of Count 

 Rumford. 



The following paper was presented : — 



Upon Logical Comprehension and Extension. By C. S. 



Peirce. 



§ 1. That these Conceptions are not so Modern as has been repre- 

 sented. 



The historical account usually given of comprehension and ex- 

 tension is this, " that the distinction, though taken in general 

 terras by Aristotle, and explicitly announced with scientific precision 

 by one, at least, of bis Greek commentators, had escaped the marvel- 

 lous acuteness of the schoolmen, and remained totally overlooked and 

 forgotten till the publication of the Port Royal Logic." * I would offer 



* This is quoted from Baines (Port Royal Logic, 2d ed. p. xxxiii.), who 

 says that he is indebted to Sir William Hamilton for the information. 



