12 



Scientific Proceedings (77). 



will recover in the solution of certain electrolytes. The recovery 

 depends upon the possibility of the diffusion of potassium salts 

 out of the egg and not of the diffusion of the outside solution into 

 the egg, since very toxic solutions of electrolytes, e. g., NH4NO3 or 

 (NH 4 ) 3 citrate, may be as efficient in bringing about the recovery 

 of the egg as comparatively harmless or beneficial salts, like NaCl 

 or NaCl + CaCl 2 or sea water. The relative efficiency of various 

 salts for the production of the "general salt effect" depends to a 

 large extent on the nature and valency of the anion and is for CI : 

 S0 4 : citrate = 1:4:16, i. e., it follows Hardy's valency rule for the 

 precipitation of proteins. This suggests that we may be dealing in 

 this case with an action on some protein. The same valency rule 

 holds not only for the acceleration of the rate of the diffusion of 

 potassium salts but also for the opposite effect; namely, the antag- 

 onistic salt action. 



Somewhat similar results were obtained for the diffusion of 

 acid into the egg and these experiments seem to indicate that for 

 the diffusion of these two groups of electrolytes, potassium salts 

 and acids, in addition to the osmotic pressure of the substance a 

 second effect is required which we call the general salt effect and 

 which consists in the modification of a certain constituent of the 

 membrane (possibly a protein) by the salt. 



9 ("87) 



The registration of heart sounds from the exposed heart and 

 large vessels. A demonstration. 



By C. J. Wiggers and A. Dean, Jr. 



[From the Department of Physiology, Cornell University Medical 

 College, New York City.] 



For a number of reasons it was questionable whether the 

 heart sounds recorded from the resonant thoracic wall are com- 

 posed of the same vibrations as those actually arising within the 

 heart. To assist in answering this question a method of registering 

 the sounds from different spots on the exposed heart and large 

 vessels was devised. The apparatus consists of a sound receptor 



