38 



Society, &c, and of his Brothers, George and Henry Hadley. 

 London. 8vo. — From Dr. Robert Hare. 



Annual Report of the Geologist of Maryland, 1840. 8vo. — From 

 the Author, Dr. J. T. Ducatel. 



The Theory of Money and Banks investigated ; by George Tucker, 

 Professor of Moral Philosophy in the University of Virginia, &c. 

 &c. Boston, 1839. 12mo. — From the Author. 



Epistle to Joseph John Gurney, on the Society of Friends; by Benja- 

 min Hornor Coates, M.D. Philadelphia, 1841. — From the Au- 

 thor. 



Rambles in Europe in 1839, with Sketches of Prominent Surgeons, 

 &c. &c. &c. ; by William Gibson, M.D., Professor of Surgery 

 in the University of Pennsylvania, &c. Philadelphia, 1841. 

 12mo. — From the Author. 



Professor Bache presented to the notice of the Society, the 

 curves representing the Magnetic Observations made at Wash- 

 ington City, on the 6th of January last, and the five days suc- 

 ceeding, a drawing of which he had received from Lieut. Gil- 

 liss, the director of the Magnetic Observatory at that station. 



Dr. Patterson presented to the Society a resolution recently 

 adopted by the Controllers of the Public Schools, agreeing to 

 deposite a transit instrument imported by. them, for five years, 

 from the 1st instant, in the Society's Observatory, on certain 

 conditions. The resolution was referred to the Committee on 

 the Observatory. 



Dr. Mitchell referred to the experiments, in which he is still 

 engaged with Dr. Hare, on the electricity produced during va- 

 porization. He mentioned that the solid, formed when car- 

 bonic acid which has been liquefied by pressure escapes from 

 the containing vessel, is found to have positive, and the re- 

 ceiver negative electricity. He proposes to communicate other 

 results of these experiments at a future meeting of the Society. 



