NUTRITION — OSBORNE. 211 



food proteins of vegetable origin. The information on record concerning the 

 proportion of products of hydrolysis of the meat proteins is very meager, for 

 it comprises but one incomplete hydrolysis of beef "syntonin." 



As nothing definite is known in respect to chemical similarities and differ- 

 ences between the proteins of the different kinds of meats, hydrolyses have 

 been made of the muscle substance of chicken and fish (halibut), the results 

 of which have been published in the American Journal of Physiology. These 

 results show that distinct differences exist in the proportion of several of the 

 decomposition products of the muscle substance of these two species. Both 

 yielded over 7 per cent of lysine, a quantity larger than has yet been obtained 

 from any other true protein, and far in excess of that found in most of the 

 seed-proteins. In respect to the proportion of their decomposition products, 

 these muscle substances more nearly resemble the proteins of the leguminous 

 seeds than those of any other group of plants, and differ most widely from 

 those of the cereals. 



Two hydrolyses of the albumin of the white and three hydrolyses of the 

 vitellin of the yolk of hens' eggs have already been published by others, but 

 their results were so divergent that it was thought advisable to repeat the 

 hydrolyses of these important food-proteins in order to show which of the 

 published figures were correct. It was also hoped to thus obtain data which 

 would show how close an agreement could be expected between the results of 

 experienced investigators working entirely independently of each other. Both 

 these expectations have been attained and the results will soon be published. 



Many data concerning the basic decomposition products of a considerable 

 number of proteins have been gradually accumulated during the last four 

 years, and especial attention has been directed to this subject during the past 

 year. An attempt has been made to determine with a high degree of accu- 

 racy the proportion of the basic decomposition products, to test the capabili- 

 ties of the available methods, and to record the best conditions for carrying 

 them out. This work has led to some important results and has recently 

 appeared in the Journal of Physiology. 



An investigation was also made of the primary or secondary origin of 

 pyrimidine derivatives of nucleic acids. Although this is not a question of 

 protein chemistry, the close association of these substances in the tissues 

 makes a knowledge of the chemistry of one important for a knowledge of the 

 chemistry of the other. As the question investigated had become the subject 

 of much controversy and was one of fundamental importance to the chem- 

 istry of the nucleic acids, it seemed worth while to devote a short time to ex- 

 periments with a supply of nucleic acid from the embryo of wheat which 

 remained over from previous investigations made in this laboratory. The 

 results of these experiments furnished conclusive proof that the pyrimidine 

 derivatives do not originate from the purines, and that they are primary 



