$34 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 Curnir’s 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 Forpyce found the circulation of the 
blood to proceed very rapidly, as his pulse gave 145 beats 
imaminute. ‘“ 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 Curnrte’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-' 
