RESULTS OF CALORIMETRIC MEASUREMENTS. 



965 



room, but provision is made for absorbing the C0 2 and water as 

 it is formed, and for adding new oxygen from an oxygen tank as it 

 is needed. This arrangement is represented schematically in 

 Fig. 301a. It is possible in this form of calorimeter to determine 

 the amount of oxygen consumed as well as the amount of carbon 

 dioxid eliminated. By this means the observer can ascertain the 



respiratory coefficient (-7^), a factor of much value, since it 



\ \J2 I 



throws light on the nature of the material undergoing oxidation 

 in the body. By means of this apparatus many interesting and 

 important experiments have been made upon the nutrition of 

 man under different physiological and pathological conditions, 

 and it seems probable that it will supplant entirely the earlier 

 forms of calorimeter described in the preceding pages. As an 

 indication of its sensitiveness the following result may be quoted 



RESPIRATION CHAMBER 

 used 



Hi \ produced 



, n- . . 



O deficient 



Fig. 301o. Diagram of circulation of air through respiration apparatus. (Atwater and Benedict.) 



from observations made upon a man who, while in the apparatus, 

 did much muscular work on a bicycle ergometer: 



Income : Potential energy of material metabolized in body = 5459 CaL 



f Energy given off from the body as heat .... 4833 Cal. 

 uutgo ^ Heat equivalent of muscular work 602 Cal. 



5435 Cal. 5435 CaL 

 Experimental error 24 CaL 



Results of Calorimetric Measurements. The actual results 

 obtained from direct calorimetric measurements corroborate those 



