NORMAL PROCESSES OF ENERGY METABOLISM 579 



the fall of potential across the terminals of the standard resistance and 

 serves to determine the current. From the heating coil in the chamber a pair 

 of wires runs out to a voltmeter. A key is provided in this circuit so 

 that the voltmeter may be connected momentarily to determine the fall of 

 potential across the terminals of the heating coil. The reading of the milli- 

 voltmeter is maintained constant by manipulation of the ballast resistance 



Fig. 29. The small calorimeter at Cornell University Medical College shown in 

 process of construction. The observer's table is at the extreme left. The Gouy regu- 

 lator is shown as a cubical box on top the calorimeter. The arrangement of heating 

 and cooling elements on the outside of the zinc wall is shown at the open end of the 

 calorimeter. The water meter E, suspended on a balance is shown at the extreme 

 right. The tank supplying the heat absorber with water under constant pressure is 

 shown at the extreme top of the picture. Water passes from this tank through a 

 pipe to the Gouy regulator, thence to a reheater at the upper left hand corner of 

 the calorimeter, thence through the heat absorber which is a grid of pipes on the 

 ceiling of the inner chamber, thence back to the meter. From the waste tank, A, 

 water is pumped up again into the pressure tank. 



and the voltmeter is read several times during each period of the experi- 

 ment. The heat dissipated is given by multiplying together the numbers 

 expressing the fall of potential across the terminals of the heating coil 

 (in international volts), the current in amperes and the time in seconds 

 and dividing by the number expressing the mechanical equivalent of heat 

 at the temperature of the flowing water. For example in a heat controlled 

 experiment performed with the small respiration calorimeter on May 6th, 

 1911, Williams obtained the following results: The strength of current, 



