394 



PHYSIOLOGICAL CHEMISTRY. 



ments the following heats of combustion have been determined. 

 Results found by different workers show slight variations, but 

 the values here are mean values and sufficient for illustration. 



FIG. 31. Bomb calorimeter (Hempel-Atwater) in which heats of combus- 

 tion of food stuffs are determined by burning in oxygen. A is the bomb 

 proper, inside of which a small platinum capsule is shown in which the sub 

 stance is contained, and ignited by means of a current led in through the in- 

 sulated wires. The bomb is immersed in water ; the increase in temperature 

 is measured by means of a delicate thermometer. 



