126 



Scientific Proceedings (38). 



In recovery, tremors, tetanic spasms, or both, and marked hyper- 

 excitability are noted. 



The results support the view that the increased ammonia in 

 the blood of parathyroidectomized animals is directly responsible 

 for the tetany and depression symptoms, as the concentration of 

 the ammonia in the blood of parathyroidectomized cats and dogs 

 is sufficient to cause tetany, tremors and depression in the normal 

 animal. 



78 (488) 



The daily curve of nitrogen elimination in the pregnant, as 

 compared with the non-pregnant dog. 



By J. R. MURLIN. 



Comparison of the daily nitrogen output in periods of three 

 hours in pregnant dogs as compared with the same dogs non-preg- 

 nant, on the same diet and living under identically the same con- 

 ditions, shows that the form of curve is essentially the same in the 

 two conditions. In the pregnant condition the total curve runs 

 below that of the non-pregnant condition at a fairly uniform dis- 

 tance, showing that the retention for the embryos and auxiliary 

 structures is fairly uniform from hour to hour. 



79 (489) 



Contraction of muscle during voluntary innervation. 

 By HORATIO B. WILLIAMS. (By invitation.) 



[From the Department of Physiology, Cornell University 

 Medical College^ 



This communication is a preliminary report of studies on the 

 frequency of contraction of voluntary muscle under voluntary in- 

 nervation. 



The muscles studied were the flexors of the forearm, and the 

 problem has been approached from three directions : 



1. The frequency of the action currents. 



2. The frequency of the sound accompanying muscular con- 

 traction. 



3. The frequency of the mechanical variations over the surface 

 covering the contracting muscles. 



