384 PHILOSOPHY OF ZOOLOGY. 



and, by means of respiration, the action of the heart $ and 

 consequently the whole circulating system, as it exer* 

 cises likewise an unlimited controul over the arteries and 

 glands in the office of secretion, it may be said to regulate 

 all the movements of vital action, and consequently the pro- 

 duction of that temperature requisite for the continuance 

 of existence. 



The digestive system is destined to furnish the means by 

 which the vital energies are to be recruited, and its indirect 

 influence over the power of an animal to regulate its tem- 

 perature, must be considerable. In Dr CURRIERS experi- 

 ments already quoted, the body, which had been much 

 cooled by exposure to cold, was most speedily restored to 

 its natural warmth, and made comfortable, by the applica- 

 tion of a bladder of hot water to the pit of the stomach. 

 In one case, during the application of the cold, the person 

 complained of a coldness and faintness at the stomach. 

 Hence this observer concluded, that there was some peculiar 

 connection of the stomach, or of the diaphragm, or both, 

 with the process of animal heat. 



The changes which take place in the circulating system, 

 viewed in connection with animal heat, are not so great as 

 might have been expected. In resisting the application of 

 heating media, Dr FORDYCE found the circulation of the 

 blood to proceed very rapidly, as his pulse gave 145 beats 

 in a minute. " The external circulation was greatly in- 

 creased ; the veins had become very large, and an univer- 

 sal redness had diffused itself over the skin." With this 

 increased rapidity of circulation in the blood, there was no 

 change, however, produced in the frequency of respiration. 

 In Dr CURRIE'S experiments, where the body was exposed 

 to a cooling medium, and where a considerable quantity of 

 heat must have been generated, the ordinary velocity of the 

 blood was diminished, and the breathing became unusual- 



