72 Society for Experimental Biology and Medicine. 



phosphate of ammonia was shown again and again by dissolving 

 it in ammonia and precipitating it from the latter solution by adding 

 concentrated nitric acid, when the characteristic crystals of the 

 molybdo-phosphate,as shown under the microscope, were formed. 

 The phosphate of this precipitate was also obtained as ammonio- 

 magnesic phosphate. When the nitric acid was allowed to act for 

 a longer time, e. g., from two to six days, at 35°C, the quantity 

 of phosphorus liberated as phosphoric acid was increased. 



Quite a different result was obtained with caseinogen. The 

 used quantity of the latter was purified by dissolving and precipi- 

 tating five times and by extracting with ether to free it from leci- 

 thin. The material so prepared did not give the slightest evidence 

 of the presence of phosphates when the nitric-molybdate reagent 

 was added and immediately thereafter some phenylhydrazin solu- 

 tion (i per cent.). When portions of the pure caseinogen were 

 dissolved in nitric acid of 1.2 sp. gr., and kept at 35 0 C, for two 

 weeks not the slightest trace of phosphoric acid was demonstrated 

 with the nitric-molybdate reagent and phenylhydrazin, and even 

 after two months only the slightest possible trace of phosphoric 

 acid was present. 



It is, therefore, to be concluded that phosphorus is combined 

 in caseinogen in a manner very different from that which obtains 

 in true nucleoproteids and that nitric acid may be employed to 

 distinguish nucleic acids and the typical nucleoproteids from para- 

 nucleic compounds. 



5i (194) 



Does the stomach of the dog contain free hydrochloric acid 

 during gastric digestion ? 



By Lafayette b. Mendel. 



[From the Sheffield Laboratory of Physiological Che mis try, Yale 



University^ 



In a recent contribution to the physiology of digestion from 

 the Physiological Laboratory of the University of Vienna, Albert 

 Miiller 1 has made the announcement that the digestion of meat 

 regularly proceeds in the stomach of healthy, normal dogs in the 



'Albert Miiller : Archiv fur die gesammte Physiologic ', 1 907, cxvi, 163. 



