f 



DESCRIPTION. 5 



Many of the forms of apparatus previously referred to were designed 

 for experiments with lower animals, but some of them were for experi- 

 ments with man. The particular apparatus here described was of this 

 latter type (though it can be, and indeed in its earlier form has been, 

 readily adapted for use with domestic animals) . Experimenting with 

 man necessarily involves certain restrictions, such as the requirement 

 of a varied and palatable diet, a rate of ventilation which shall insure 

 proper purification of the air, an experimental period not unduly long, 

 etc. ; but it is obvious that in investigations of the problems of nutri- 

 tion of man it is a decided advantage to experiment directly with man. 

 Otherwise, if domestic animals were used, it would be necessary to draw 

 conclusions for omnivora (man) from results obtained with carnivora 

 (dogs) or herbivora (sheep or cattle). Furthermore, in experimenting 

 with apparatus as elaborate as this must necessarily be, it is of the 

 greatest value to have the intelligent cooperation of the subject within 

 the apparatus ; and the fact that there may be reasonable control of the 

 muscular activity and sleep is also an advantage. 



As will be seen from the more detailed description beyond, the cham- 

 ber of the apparatus is large enough to allow a man to stand or lie down 

 at full length, and to move about to a limited extent, and it is provided 

 with a chair, table, and bed, that may be folded up and put aside when 

 not in use, so that the subject may sit, or lie down, or stand and move 

 about at will, or as the conditions of the experiment prescribe. When 

 the experiment involves muscular work, a suitable device on which 

 work may be performed, and by means of which the amount of work 

 done may be determined, is also provided. A window in one end of 

 the chamber admits ample light for reading and writing, and as it faces 

 a window in the laboratory, even allows something of a view out of 

 doors. A telephone affords opportunity for communication with per- 

 sons outside the apparatus. The air is kept constantly in circulation, 

 the impurities removed from it, and oxygen restored to it. The 

 temperature of the chamber is maintained very uniform, whatever the 

 conditions of activity of the subject. Receptacles for food, drink, and 

 excreta are introduced or removed through an aperture provided for 

 the purpose. Every attempt is made to keep the subject comfortable 

 and to have the conditions as nearly normal as possible. 



DESCRIPTION OF THE APPARATUS IN ITS EARLIER FORM. 



The respiration calorimeter at Wesleyan University has been in pro- 

 cess of development about twelve years. Several publications describ- 

 ing the earlier form of apparatus, with modifications and improvements, 

 and reporting the experiments made with it, have been issued. 



