STARCH EQUIVALENTS 



191 



Two of these methods have been employed in 

 "monthly notes" in assessing the starch equivalent 

 of foods, the first based on calculation from the nett 

 heat value to the animal of the various nutrients 

 contained in the food, the second purely experi- 

 mental. The nett heat values of the various nu- 

 trients have been ascertained experimentally by 

 means of the respiration calorimeter, a compli- 

 cated apparatus which enables the experimenter to 

 feed an animal as large as an ox on a weighed 

 and analysed diet, to collect, weigh and analyse the 

 whole of his excreta both solid, liquid and gaseous, 

 and to measure the amount of heat he gives out. 

 By means of this apparatus it has been found that 

 the nett heat values of the nutrients digested by 

 an animal such as an ox are as follows: 



TABLE III. 



These values are the nett values realized in the 

 animal's body. They differ from the amount of 

 heat given out when nutrients are burned outside 



