305 



derson, M. D. Assistant Surgeon United States Army. Philadel- 

 phia, 1840. Svc — From the same. 



Prof. Frazer, from the Committee on Dr. Kane's proposed 

 Expedition to the Arctic regions, reported a Memorial to Con- 

 gress on that subject, which the Committee recommend for 

 adoption by the Society. The Memorial was read, considered 

 and adopted, and was ordered to be signed by the proper offi- 

 cers and forwarded to both Houses of Congress. 



The Rev. Dr. Boardman exhibited to the Society a specimen 

 of rock-crystal, from the Alps, of unusual clearness and beauty. 

 It is cut and polished in a graceful form and manner. Length, 

 4| inches; diameter, 2\ by 2 inches. 



Judge Kane referred to the experimental trial of the calo- 

 ric-engine vessel, recently made at New York. He had 

 been assured by gentlemen who were on board the vessel, a 

 clipper-built ship of about 2000 tons burthen, that the engine, 

 on a first trial, and under unfavourable circumstances, pro- 

 pelled the vessel at a rate of more than six miles per hour: the 

 maximum speed, with the wind, was fifteen miles per hour. 

 The amount of fuel consumed during the trip was between one- 

 quarter and one-fifth of that required for a steam-engine of the 

 same power; and a great advantage also results from the lesser 

 space occupied by the caloric-engine, and the greater safety 

 from fire. 



The Judge remarked that, if there was no mistake in all this, 

 it would seem that the time anticipated by scientific mechanics 

 had now come, Vv^hen the steam-engine would become one of 

 the things that were. 



Mr. Justice said that the beautiful specimen of rock-crystal, 

 shown this eveningj reminded him of a phenomenon recently 

 observed by him in his microscopical observations — and asked 

 for information on the subject. A portion of the ordinary sil- 

 vering solution was evaporated, and the crystals, while on the 

 hot slide of the microscope, exhibited no evidence of polariza- 

 tion of light; but on cooling the ordinary display of beautiful 

 colours appeared. 



Mr. Trego, from the Committee of Publication, presented 



