tf(j Dr. Marcet. Absorption of Oxygen and [June 4, 



expired. The mean proportion of oxygen absorbed in the oxygen 

 inspired amounted to 3'57 per cent. 



The weight of oxygen consumed per hour varies according to the 

 person under experiment, and also in relation to the lapse of time 

 after the ingestion of food. It ranged in my case from 19'75 grams 

 to 22-02 ; and per kilo, weight of my body, from 0'338 to O376 

 gram. This is a much smaller proportion than that given for 

 animals either fey Eegnault and Reiset or Chapman and Brubacker. 



Influence of Food. Food, in my case, at a mean time of 2 hours 

 and 16 minutes after its ingestion, exerted apparently no effect on the 

 proportions of C0 2 , 0, and N expired, as they were nearly exactly 

 the same in both cases. 



The ratio between the oxygen consumed and C0 2 produced exhibited, 

 in my case, a decided tendency to fall while under the fasting state, 

 the figures obtained being 0'870 while under the influence of food, 

 and 0'850 while fasting. 



The volumes of oxygen absorbed were much the same in both 

 cases, although exhibiting a tendency to rise while fasting. 



The differences between the proportions of oxygen absorbed in 100 

 volumes of air, or 100 of oxygen, under the influence of digestion or 

 fasting are inappreciable. 



There is a decided excess in the weight of oxygen consumed under 

 the influence of food over that consumed fasting ; the figures being 

 21'37 grams after food, and 20'26 grams fasting. 



The weight of C0 a expired per minute varies as usual according 

 to the influence of food, and calls for no comment. 



Mr. Russell also submitted to twelve experiments, six made at a 

 mean time of two hours after a meal, and six while fasting, or at a 

 mean time of four hours and twenty-three minutes after food. The 

 proportions per cent, of C0 2 , 0, and N expired are much alike in 

 every experiment, varying as follows : C0 2 , 5 '38 to 5'96 ; O, 14'39 

 to 15-26 ; N, 79-36 to 79'92. The ratio of oxygen consumed to CO 2 

 produced varies from 0'818 to 0'923, with a mean of 0'878. This 

 closely approximates the corresponding means obtained in my own 

 case, amounting to 0'863, which, however, is slightly lower. The 

 next figures in the table, showing the proportion of oxygen con- 

 sumed on 100 of air and 100 of breathed, give means very nearly 

 the same as when I submitted to experiment. 



The weights of oxygen consumed per hour, 25'98 grams, and per 

 kilo, of body weight per hour, 0'380, are decidedly higher than in my 

 case. Mr. Russell also expired a greater weight of C0 3 per minute 

 than I did, showing greater activity in the process of nutrition a 

 phenomenon probably due to youth. 



The influence of digestion and fasting shows no alteration in the 

 proportions of C0 2 , 0, and N expired. The difference in the ratio 



