July 16, 1915] 



SCIENCE 



81 



outdoor air were made by Miss Alice John- 

 son, proved conclusively that the percentage 

 of carbon dioxide and oxygen in uncon- 

 taminated outdoor air remained constant 

 throughout the entire year, irrespective of 

 wind direction and temperature. Speci- 

 mens of normal air secured at numerous 

 places on the Atlantic Ocean and on the 

 top of Pike's Peak showed the same re- 

 markable uniformity. By this study we 

 were provided at one and the same time 

 with a standard for testing all gas-analysis 

 apparatus and definite knowledge regard- 

 ing the composition of inspired air, thus 

 doing away with the necessity for the innu- 

 merable analyses that otherwise would be 

 essential. 



The investigations on diabetes in con- 

 junction with Professor Elliott P. Joslin 

 have shown in the first place that during 

 severe diabetes there is a distinct increase 

 in the basal metabolism of the patients. 

 It has also been shown that this increased 

 metabolism in diabetes is due to the fact 

 that with the abnormal breaking down of 

 food materials in the body of the diabetic 

 there is developed an excessive amount of 

 acid, chiefly B-oxybutyric acid, which 

 directly stimulates the cells to a greater 

 activity. "With treatment reducing the 

 acidity and particularly with the new, re- 

 markable Allen treatment this increased 

 metabolism entirely disappears. 



In addition to the study of diabetics, a 

 number of other projects have received 

 consideration at the Nutrition Laboratory. 

 Among these are the study in conjunction 

 with Dr. F. B. Talbot of the metabolism of 

 normal and atrophic infants and of infants 

 in the first hours of post-natal life. The 

 importance of knowing the energy require- 

 ments and the character of the combustion 

 in the body of the new-bom infant has 

 justified an extended research on this sub- 

 ject in which we have studied over 100 



infants within the first few hours after 

 birth. The new-born babies were taken 

 from the hospital immediately after birth, 

 placed in the respiration chamber and there 

 studied for several hours, very careful 

 records of the carbon dioxide produced 

 and the oxygen consumed being made. The 

 observations on atrophic hospital infants 

 have supplied values of particular signif- 

 icance in interpreting a number of so-called 

 "physiological laws." Indeed, one of the 

 best methods of studying physiology is to 

 study abnormal physiology. 



In connection with the respiration experi- 

 ments on infants a knowledge of the exact 

 degree of repose of the subject is of impor- 

 tance. I have already shown the enormous 

 influence of severe muscular activity upon 

 the metabolism of man, and it is evident 

 that if, in securing normal data regarding 

 infants, to be subsequently used for com- 

 parison with pathological eases, we do not 

 take cognizance of the influence of even mi- 

 nor muscular activity, we are liable to great 

 error. Thus, it would be wholly irrational 

 to compare the metabolism of a normal, 

 healthy infant, but moving and restless, 

 with that of a weak, emaciated infant lying 

 perfectly quiet. Nor is it sufScient to sup- 

 plement our measurements of the respira- 

 tory exchange by records of ocular obser- 

 vations of the activity, for experience 

 quickly showed us that these were wholly 

 inadequate. A method has therefore been 

 devised for automatically recording the 

 muscular activity. The crib in which the 

 baby is placed rests at one end on two fric- 

 tionless steel points. The other end is sup- 

 ported by a spiral spring having a rubber 

 tube about it. As the infant moves, the 

 air inside of the rubber tube expands or 

 contracts and by means of the air trans- 

 mission any changes in this tension may be 

 recorded with a delicate tambour and 

 writing point. This adjustment may be so 



