l88 REPORTS O? INVESTIGATIONS AND PROJECTS. 



England Deaconess Hospital placed every facility at their disposal, and a 

 series of respiration-calorimeter experiments was carried out with a degree of 

 success hardly anticipated at the inception. The hospital expenses were borne 

 by a grant made to Dr. Murlin by the Rockefeller Institute for Medical 

 Research. 



Three complete cases were studied for several days before delivery and for 

 several days after delivery. The intra-uterine metabolism compared with the 

 extra-uterine metabolism was sufficiently sharply studied to allow positive de- 

 ductions to be drawn. The results will be published shortly. 



A COMPARISON OF DIRECT VS. INDIRECT CAEORIMETRY. 



The Nutrition Laboratory is in a peculiarly favorable position to compare 

 the two principal methods of studying the transformations of energy in the 

 human body. The earlier method consisted in making chemical studies of 

 the excreta, solid, liquid, and gaseous, and computing therefrom the kinds and 

 amounts of material transformed in the body. From the relatively constant 

 heat of combustion of protein, fat, and carbohydrate, it is possible to com- 

 pute indirectly the heat production of man. This method has long been 

 employed in many of the European laboratories, and in lieu of direct cal- 

 orimetric measurements is of very great value. It has been believed by some, 

 however, that for short experiments the method of indirect calorimetry is 

 not accurate, and unfortunately the larger number of researches in indirect 

 calorimetry have been made with experiments of short duration. 



With the calorimeters available in this laboratory and with the number of 

 different forms of respiration apparatus, it was believed that an extended 

 investigation into the comparison of direct and indirect calorimetry should 

 be made. From the results of the long 24-hour experiments published in the 

 earlier reports, it has been seen that the direct and indirect calorimetry for 

 periods of 24 hours agree perfectly as far as physiological experiments can 

 be presumed to agree. Indications have pointed, however, to the fact that in 

 short experiments there are relatively wide discrepancies that can not as yet 

 be explained. A study of these discrepancies and a study into the compari- 

 son between direct and indirect calorimentry in experiments of one or two 

 hours have occupied our attention considerably during the past year. 



COMPUTATIONS. 



The simultaneous determination of the large number of factors in the 

 metabolism of man involves an extended series of calculations for each 

 experiment, and hence the work of the computing division is of great impor- 

 tance in the proper calculation of the results of the different experiments. 

 During the past year the calculation and tabulation of the results of a large 



