212 EXPERIMENTAL PHYSIOLOGY. 



while in the calorimeter. The hand of the subject, who is sitting 

 on a high chair, is then placed in water at about 30-32 C. contained 

 in the large bath (the temperature of the water is taken by an 

 ordinary thermometer) and it is left there for ten minutes, or so, in 

 order that the skin and other tissues of the hand may be brought 

 to the same temperature as the water. By so doing, conditions 

 are established which are analagous to those which would exist if 

 the blood vessels were alone suspended in the water bath. The 

 opposite hand is covered with a glove, or placed in the pocket, so 

 that it may not become cooled and so cause reflex vaso-constric- 

 tion in the observed hand. While the hand is being brought 

 to the correct temperature, 3,000 c.c. of water is removed from 

 the large bath and placed in the calorimeter, the hand opening 

 of which is then closed by the felt lid. The water is occasionally 

 stirred by the feathers, the thermometer is placed in position, and 

 the telescope adjusted so that an exact reading of the temperature 

 may be taken. 



When the ten minutes is up, the hand is withdrawn from the 

 bath, the wrist quickly wiped dry with a towel, the hand with the 

 fingers extended carefully passed through the hand opening into 

 the water in the calorimeter, and the subject instructed to keep the 

 fingers abducted and extended and not to move them. He must 

 also be warned not to touch the thermometer. The felt collar is 

 placed round the wrist and the height of the calorimeter is adjusted 

 so that the subject does not require to strain his body in order to 

 keep the hand in the correct position (or with the upper skin line 

 at the edge of the felt collar). 



The observer sits on a low stool behind the subject, and having 

 noted the time, and stirred the water in the calorimeter, proceeds 

 to record the temperature. The stirring is maintained throughout 

 the observation, which lasts 10 minutes, and the thermometer is 

 read every 2 minutes. When time is up, the felt collar is removed, 

 the hand carefully withdrawn, and the hand opening covered by 

 the felt lid. It is necessary to observe the temperature in the 

 calorimeter for a further period of 10 minutes, with constant stirring, 

 so as to determine the extent to which it is losing heat to the air 

 (the self-cooling of the calorimeter). 



The volume of the hand is determined by placing it, while still 



