NUTRITION INVESTIGATIONS. 25 



upon the body made by severe muscular and mental work. The ex- 

 periments in which muscular work Avas the feature were made with 

 a professional athlete, and from the recorded data it is possible to 

 compute the mechanical efficiency of the body as a machine. 



The subjects for the experiments on mental work were students of 

 Wesleyan University, who took their college examinations in the 

 respiration chamber of the calorimeter, spending there a period of 

 not less tlian three hours per day. For purposes of comparison a 

 control experiment was made with each student in which the subject 

 passed the same period of time in the respiration calorimeter chamber 

 without mental work of any special kind or amount. 



A considerable number of experiments were also made to study 

 the normal food and euerg}^ requirements of individuals of different 

 physique. The subjects were two tall, thin, young men, both over 6 

 feet in height. Five experiments of this nature were also conducted 

 with women. Experiments such as these are admirably adapted for 

 showing the nornuil physiological factors for Avater, carbon dioxid, 

 and oxygen requirement for different individuals, and furnish data 

 for establishing certain definite standards based upon weight, sex, 

 height, and general j^hysique which are more accurate than those 

 commonly in use at the present time. 



A number of improvements have been made in the construction 

 and operation of the respiration calorimeter and in the study of ex- 

 perimental methods. 



Cooperating with the Bureau of Animal Industry of this Depart- 

 ment, an extended series of experiments on the digestibility and nu- 

 tritive value of cheese has been undertaken. This work has so far 

 progressed that it is fair to conclude that cheese may be eaten in large 

 amounts without digestive disturbances and that it is very thoroughly 

 assimilated and a cheap and useful source of protein. 



The Caniegie Institution, of AVashington, has continued grants for 

 research with the respiration calorimeter, by which the apparatus has 

 been developed in such a way that the income and outgo of ox3'gen 

 may be directly measured, and a number of metabolism experiments 

 have been made with the improved apparatus, both for the Office of 

 Experiment Stations and for the Carnegie Institution. 



A considerable amount of editorial work is carried on at Middle- 

 town, including calculations, verifications of results obtained in the 

 cooperative investigations, the collating of the results of the work 

 of other investigators, and the j^reparation for i)ublication of the 

 results of the experimental work at Middletown and at cooperating 

 institutions. This editorial work has been in charge of R. D. Mihier. 



Dietary studies have been conducted at the Hawaii Agricultural 

 Experiment Station, under the direction of Dr. Ednuind C. Sliorey, 

 in the family of a professional man and with pupils of a native 



