1913] Alfred P. Lothrop 545 



the weight of wool taken for the corresponding weight of melanin ; 

 and I find that the percent of nitrogen in the keratin structure 

 (white wool) would be only 15.48 per cent. It can be readily 

 Seen that this is far too great a divergence from the white wool 

 percentage (16.27) to be an experimental error. It is far more 

 probable that the melanin molecule is broken down by acid hydroly- 

 sis and that only a portion of the nitrogen is obtained as humin 

 nitrogen, so that the correction which I used did not take into 

 account a considerable portion of the melanin molecule which has 

 a lower nitrogen content than the keratin structure. This suppo- 

 sition is in agreement with the results of my previous work. 



88. Metabolism studies of five cases of endarteritis oblit- 

 erans ("Hebräische Krankheit"). Max Kahn. {Service of 

 Dr. Charles Goodman, Beth Israel Hospital, New York.) In five 

 male adults suffering from endarteritis obliterans of the vessels of 

 the leg, and fed a Folin diet, the urinary nitrogen partition was 

 normal, and the excretion of ethereal sulfate and calcium was 

 increased. 



8g. On the content in expired air of protein detectable by 

 the anaphylactic reaction. Daniel R. Lucas. (Chemical Lab- 

 oratory, College of the City of New York.) The lethal intraperi- 

 toneal dose of dog serum for normal guinea pigs is about 5 c.c. for 

 300 grams of body weight; 4 c.c. for the same weight is usually 

 followed by recovery, 6 c.c. by death. The lethal dose of human 

 serum is about 10 c.c. for 300 grams of body weight. 



Two c.c. of dog serum or 15 c.c. of distilled water, injected 

 intraperitoneally, in normal guinea pigs, caused shivering, twitch- 

 ing and noisy respiration. Such Symptoms have been interpreted 

 as evidences of anaphylactic shock but are not reliable indications 

 of it. Proportionate amounts and the production of a lethal effect 

 by a sublethal dose are essential for accuracy when dog serum is 

 used. Intraperitoneal injections (2-15 c.c.) of condensations from 

 the expired air of dogs did not sensitize guinea pigs to dog serum. 

 Guinea pigs exposed to dog exhalations for a week, under condi- 

 tions of very poor Ventilation, were not sensitized. Nor were any 

 evidences of sensitization to human serum obtained when pigs were 

 exposed for a week in the exit of a Ventilation System in a College 

 building containing many people daily. 



