238 CARNEGIE INSTITUTION OF WASHINGTON. 



For the first time in its history, therefore, the Laboratory appears to 

 be to a certain extent misnamed. Respiration calorimeters, respiration 

 apparatus, intricate gas-analysis apparatus, and special devices for 

 physiological and psychological measurements do not lend them- 

 selves primarily to a study of the economic or sociological phases 

 of nutrition problems. On the other hand, it is believed that the 

 Laboratory is both morally obUgated and well fitted to contribute 

 somewhat to a solution of many of the important present-day prob- 

 lems. An extended investigation has therefore been projected in which 

 the question of the physiological effect of a reduced ration upon a 

 selected group of normal young men is to be studied in detail. 



It is somewhat difficult to plan with absolute certainty any physio- 

 logical experiments of an extended nature, using men as subjects, and 

 it is obviously necessary to modify somewhat the plan of procedure 

 as the research progresses. It can be seen that this projected study is 

 of a character much more in line with those formerly carried out at 

 Wesleyan University under the direction of Professor W. O. Atwater 

 than the problems previously studied in the Nutrition Laboratory, for 

 not only is it of prime physiological importance as an attempt to 

 throw light upon the ability of the human organism to subsist upon a 

 materially reduced ration, but it is also of direct economic importance. 



While it has been the custom in the annual reports of this Lab- 

 oratory to consider not only investigations actually in progress, but 

 likewise those contemplated, emphasis is laid upon this new project 

 primarily to call special attention to the fact that the main work of the 

 Laboratory must still remain that of abstract research, and can wisely 

 be diverted only in part to economic problems. As will be seen later in 

 this report, although the Laboratory is not primarily adapted for the 

 study of such problems, the staff is using every effort to utilize the 

 resources of the Laboratory as may seem wise and feasible in helping 

 to solve those of immediate national importance. 



ADDITIONS TO EQUIPMENT. 



APPARATUS FOR MEASURING TEMPERATURE OF COLD-BLOODED ANIMALS. 



The slight differences between the body-temperature of cold-blooded 

 animals and the temperature of their environment — differences which 

 at times play a very important r61e in the metaboUsm of the animal — 

 necessitate a fine degree of measurement. After preliminary experi- 

 mentation, in which determination was made of the temperature be- 

 tween the coils of a large python, each respiration chamber was equipped 

 with a thermal junction which gave the exact temperature of the 

 environment and with a modification of the pyrovolter with appropriate 

 galvanometers. This addition to our already extended equipment in 

 the special laboratory at the New York Zoological Park makes it 



