244 



of the valves of the arteries, veins, and some other portions of the hu- 

 man structure; they were tiierefore, in principle, as old as the crea- 

 tion oi^ man. 



These valves, he observed, are applicable generally, to all the pur- 

 poses ofordinary valves, but particularly so to flexible tubes; in which 

 application they are now presented in syringes of an economical form. 



Mr. Peale then desired permission to state the advantages which he 

 believed these valves possessed, and for which letters patent of the 

 United States had been granted to him, the drawings with which ex- 

 hibited their structure fully, and were now presented for inspection. 



1. Their extreme simplicity of form, and economy of construction. 



2. Their non-liability to injury, as they may fall, be bent, or even 

 beaten or trodden upon, without derangement. 



3. Their indestructibility, except by agents that would destroy the 

 whole fabric or instrument. 



4. Their operation in any position, vertical, horizontal, or upside 

 down. 



Mr. Peale then showed the practical operation of valves con- 

 structed according to this mode, as applicable to various pur- 

 poses. 



Stated Meeting, March 20. 



Present, seventeen members. 



Prof. Cresson, Vice-President, in the Chair. 



Letters were read: — 



From the Natural History Society at Emden, dated Oct. 2, 

 IS56, on transmitting a donation to the Library: — 



From the Linnean Society, dated Soho Square, London, 

 Nov. 25, 1856, returning thanks for Nos. 53, 54, of the Pro- 

 ceedings of this Society: — 



From the Massachusetts Historical Society, dated Boston, 

 Feb. 19, 1S57; and from the Smithsonian Institution, dated 

 Washington, March G, 1S57, acknowledging the receipt of No. 

 56 of the Proceedings: and — 



PVom Mr. E. Godfrey Rehrer, dated Harrisburg, March 2, 



