We have received 399 books and pamphlets during the year by exchange 

 and 40 by donation ; in all, 439. Of these, 292 are volumes and 14 are 

 pamphlets. 



Eighteen letters were written during the year in answer to correspon- 

 dents, and in informing corresponding members of their election, and 54 

 acknowledgments to various Societies of the receipt of their exchanges 

 sent out. 



Three dollars and eighty-five cents was expended for postage, postal 

 cards, and envelopes, and $5.00 still remains in the hands of the Corres- 

 ponding Secretary. No receipts. 



Respectfully submitted, Edw. Evers, Cor. Sec. 



Specified List of Exchanges. — United States and Canada. 140; Germa- 

 ny, 108: Great Britain, 32: France, 31; Italy, 18; South America and 

 Mexico, 15; Holland, 12; Switzerland, 12; Russia. 10; Belgium, 9; East 

 India, 7; Spain, 6; Sweden, 5; Denmark. 3. 



In lieu of a report, the Treasurer sent the followino- commu- 

 nication : 

 Prof. F. E. Nipher, PresH Academy of Science of St. Louis. 



Before my departure for Europe I intended to render a full report to the 

 Academy of the financial standing, but regret that it was impossible for 

 me, to find time to do so. However, I can state that the Academy, accord- 

 ing to my accounts, has $127.20 to draw against, and I have authorized 

 my cashier to honor any bill of the Academy that has been signed by the 

 President and Secretary, whatever amount it may be. 



Respectfully yours, Enno Sander. 



The following donations to the Academy library were received 

 with thanks: United States Census Report, 1880, from Dr. Ev- 

 ers ; Publications of the Iowa Weather Service, presented by Dr. 

 Hinrichs. 



The Corresponding Secretary was instructed to complete the 

 file of the Academy's "Transactions" at the library of the Univer- 

 sity of Strassburg. 



Mr. Eliot C. Jewett described a very practical method, adopted 

 by himself, for determining very quickly, and with accuracy much 

 within the limits af a carat, the value of alloys of gold and silver 

 based upon a determination of their speeific gravities. 



By a large number of determinations he had found that the relation 

 between the specific gravity and the value of these alloys was very nearly 

 constant, and, by plotting this relation in a large number of cases by the 

 use of the ordinary system of coordinates, the resulting curve seems to be 

 approximately a straight line, for each point of which the abscissa repre- 



