96 CALORIMETERS FOR STUDYING RESPIRATORY EXCHANGE, ETC. 



ROUTINE OF AN EXPERIMENT WITH MAN. 



In the numerous previously published reports which describe the con- 

 struction of and experiments with the respiration calorimeter, but little 

 attention has been devoted to a statement of the routine. Since, with the 

 increasing interest in this form of apparatus and the possible construction 

 of others of similar form, a detailed description of the routine would be of 

 advantage, it is here included. 



PREPARATION OF SUBJECT. 



Prior to an experiment, the subject is usually given either a stipulated 

 diet for a period of time varying with the nature of the experiment or, as 

 in the case of some experiments, he is required to go without food for at 

 least 12 hours preceding. Occasionally it has been deemed advisable to 

 administer a cup of black coffee without sugar or cream, and by this means 

 we have succeeded in studying the early stages of starvation without making 

 it too uncomfortable for the subject. The stimulating effect of the small 

 amount of black coffee on metabolism is hardly noticeable and for most 

 experiments it does not introduce any error. 



The urine is collected usually for 24 hours before, in either 6 or 12 hour 

 periods. During the experiment proper urine is voided if possible at the 

 end of each period. This offers an opportunity for studying the periodic 

 elimination of nitrogen and helps frequently to throw light upon any pecu- 

 liarities of metabolism. 



Even with the use of a long-continued preceding diet of constant com- 

 position, it is impossible to rely upon any regular time for defecation or for 

 any definite separation of feces. For many experiments it is impracticable 

 and highly undesirable to have the subject attempt to defecate inside the 

 chamber, and for experiments of short duration the desire to defecate is 

 avoided by emptying the lower bowel with a warm-water enema just before 

 the subject enters the chamber. Emphasis should be laid upon the fact 

 that a moderate amount of water only should be used and only the lower 

 bowel emptied, so as not to increase the desire for defecation. 



The clothing is usually that of a normal subject, although occasionally 

 experiments have been made to study the influence of various amounts of 

 clothing upon the person. There should be opportunity for a comfortable 

 adjustment of the stethoscope and pneumograph, etc., and the clothing 

 should be warm enough to enable the subject to remain comfortable and 

 quiet during his sojourn inside the chamber. 



The rectal thermometer, which has previously been carefully calibrated, 

 is removed from a vessel of lukewarm water, smeared with vaseline, and 

 inserted while warm in the rectum to the depth of 10 to 12 centimeters. 

 The lead wires are brought out through the clothing in a convenient position. 



