192 REPORTS ON INVESTIGATIONS AND TROJECTS. 



secured from the laboratory of the Massachusetts Institute of Technology, 

 we have found that when a correction is made for the error referred to our 

 analyses show that the outdoor air remains remarkably constant in composi- 

 tion with regard to both the carbon-dioxide content and the oxygen content. 

 The results of the research will be prepared for publication shortly. 



Samples of air taken by Messrs. Carpenter and Higgins while on their 

 ocean voyages and samples of air kindly forwarded by Drs. Haldane, Doug- 

 las, and Yandell Henderson from Pikes Peak are now being analyzed. 



PUBLICATIONS. 

 The following have been prepared and issued during the past year : 



(1) The influence of the preceding diet on the respirator}' quotient after active digestion 



has ceased. Francis G. Benedict, L. E. Emmes, and J. A. Riche. Amer. Jour. 

 Physiol., 27, p. 383. 191 1. 



-It has commonly been believed that 12 hours after the ingestion of food, 

 active digestion ceases and that then the oxidating processes of the body 

 result in a combustion of body material. With the same individual, there- 

 fore, the kind of material oxidized 12 hours after the last food is taken 

 would be expected to remain essentially constant. This may be determined 

 by measuring accurately the carbon dioxide excretion and the oxygen con- 

 sumption, the ratio between these two — the so-called respiratory quotient — 

 being a very important index as to the character of the material oxidized. 

 In order to study the influence of the preceding diet on the respiratory quo- 

 tient after active digestion has ceased, a series of experiments was planned 

 in which the last meal of the day before contained a large or small propor- 

 tion of carbohydrates. The respiratory quotient as determined the next 

 morning, or 12 hours after these diets, showed noticeable differences in the 

 character of the material burned, being almost invariably much higher, indi- 

 cating a carbohydrate combustion after a meal high in carbohydrates and 

 lower after a meal low in carbohydrates. In these experiments, which were 

 made with seven different subjects, both the small respiration apparatus and 

 the respiration calorimeter were used. The results of the experiments permit 

 many interesting theoretical considerations as to the ratio of carbohydrate 

 material, i. e., glycogen, in the body. A number of suggestions are made in 

 this paper with reference to further experimental work. 



(2) The respirator}' exchange as affected b}^ body position. L. E. Emmes and J. A. 



Riche. Amer. Jour. Physiol., 27, p. 406. 191 1. 



In order to secure the minimum metabolism of man for purposes of 

 comparison, the gaseous metabolism has been usually measured when the 

 subjects are lying with muscles relaxed on a couch. For the purpose of 

 obtaining data regarding the metabolism of a subject in the sitting position, 

 as compared with his metabolism when lying down, some 16 experiments 

 were made with two young men as subjects. The results showed that the 

 average pulse-rate rose from 63 when the subject was lying down to 71 when 

 he was sitting, the carbon dioxide increased 4.3 per cent, and the oxygen 

 consumption 7.6 per cent. The authors conclude that the difference in metab- 

 olism is due primarily to difference in internal muscular activity necessitated 

 by the sustaining of body parts. Accordingly they infer from these tests 

 that if it were possible so to support the body of a subject in a sitting posi- 

 tion that the pulse-rate would be no greater than when the subject was lying 

 down, the metabolism would be essentially the same in both positions. 



