150 PROCEEDINGS OP THE ACADEMY OP 



of subscription to the Proceedings at twenty-five dollars was concurred 

 in. 



The following was adopted : 



Resolved, That the price of the volumes of Proceedings for 1857 and 

 '58, already completed, and that for 1859 when completed, be uniform 

 with that of the previously published volumes, (two dollars.) 



May 3d, 

 Mr. Lea, President, in the Chair. 



Thirty-eight members present. 



Dr. Leidy called attention to a fragment of jaw of Mososaurus pre- 

 sented this evening, in which the tooth of succession was preserved in 

 the cavity beneath the worn projecting tooth. 



Dr. Carson exhibited some Chinese chemicals, and remarked specially 

 upon a calomel in crystalline scales resembling boracic acid, which was 

 formed by the empirical process of subliming a mixture of alum, com- 

 mon salt and mercury. It is quite free from corrosive sublimate. 



May 10th. 



Mr. Lea, President, in the Chair. 



Forty-nine members present. 



The following papers were presented for publication in the Proceed- 



ings 



Description of a third genus of Hemiram pilings, by Theodore Gill. 



Description of seven new species of Uniones, &c, by Isaac Lea. 



And were referred to Committees. 



Dr. R. E. Rogers, by request of the Academy, gave a lecture on the 

 correlation of forces, illustrated with numerous experiments, showing 

 the mutual convertiblity of different kinds of force. 



The number of the Proceedings of the Academy for April was laid 

 on the table. 



May 11th. 

 Mr. Lea, President, in the Chair. 



Forty-nine members present. 



Dr. Leidy called attention to specimens of Palseotrochus presented 

 this evening by Prof. E. Emmons, from subsilurian strata : he stated 

 that its organic nature had been denied by able authorities, but con- 

 sidered that its symmetry and uniformity were in favor of its being a 

 fossil; it had most strongly the appearance of a coral. 



Dr. Le Conte had seen a similar body of larger size from the copper- 

 bearing rocks of Point Keewenaw, Lake Superior. He could not con- 

 ceive that such numbers of masses of similar form could arise from 

 molecular action forming concretions. 



[May 7 



