Mr. Englei" exhibited a model and explained some of the pro- 

 perties of an elliptic hyperboloid. 



Prof. Nipher exhibited and described the operation of a Thomp- 

 son calorimeter. 



Afril i6th, 1888. 



President Nipher in the chair ; eight members present. 



A letter from the President of the American Philosophical So- 

 ciety was read inviting the cooperation of this Academy in per- 

 fecting a language for learned and commercial purposes, based 

 on the Aryan vocabulary and grammar in their simplest forms, 

 and to that end purposing an International Congress, the first 

 meeting of which shall be held in London or Paris. 



May 7M, 1888. 



President Nipher in the chair ; four members present. 



Dr. Hambach read a paper on pathologic conditions of Pentre- 

 nntes, and exhibited specimens in which a portion of the ambu- 

 lacral field had been destroyed, and subsequently restored by a 

 process of secretion. The paper was referred to the Committee 

 on Publication. 



Mr. Engler exhibited and described a model of an elliptical 

 torse. 



May 21st, i< 



President Nipher in the chair ; sixteen members present. 



A paper by Dr. C. Liideking, entitled " Contribution to the 

 Chemistry of Combustion," in which he described experiments 

 showing that nitrogen of the atmosphere takes part chemically, 

 generally, in the combustion of carbon compounds, forming tran- 

 siently cyanogen or hydrocianic acid, was read by the Secretary. 

 Referred to the Committee on Publication. 



Prof. Nipher read a paper showing the limiting conditions for 

 the winding of shunt dynamos. Referred to the Committee on 

 Publication. 



