NORMAL PROCESSES OF ENERGY METABOLISM 569 



Berthelot (a) introduced the method of burning substances in oxygen 

 at high pressure, but because of the high cost of the apparatus' it did not 

 come into general use for some years after it was described. The essential 

 parts of the original apparatus were a double-walled copper vessel filled 

 with water in which was immersed the vessel capable of holding the oxy- 



Topper * 



s Motor 



thermometer 



.. Release 



Button 



Release Button '' 



Ignition Circuit 



Contacts 



Ignition Switch 



fuse Wire 



Ignition and 

 Resistance CoH 



Topper Button-^ 



(Attachment Plug for 

 \ Motor and tgn' 



I Controlling Motor speed. 

 \Sptedshvjldb9 

 {about 300 R P.M. 



Fig. 23. The bomb calorimeter of Riche for use with Berthelot bomb. The Wein- 

 holdt cup which is placed inside the box and into which the pump is lowered is not 

 shown. 



gen under high pressure together with the substance to be burned. This 

 vessel constructed of heavy steel nickeled on the outside and lined with 

 platinum became known as the Berthelot bomb, and whatever the modifica- 

 tion from the original pattern it is still known by the inventor's name. 

 The outer container filled with water is the calorimeter proper. A success- 

 ful modern construction is that of Riche shown in Fig. 23. It consists of a 



