b ON THE INFLUENCE 



spirations were made from 30 to 35 times in a 

 minute. The action of the heart at first was strong 

 and frequent : but at the end of one hour and 40 

 minutes the pulse had fallen to 24 in a minute. 



The blood in the arteries was seen of a florid 

 red, and that in the veins of a dark, colour. 



A small opening was made in the abdominal 

 muscles, through which the bulb of a thermo- 

 meter was introduced into the abdomen, and 

 allowed to remain among the viscera. 



At the end of an hour the heat in the abdomen 

 had fallen from 100 to 89. At the end of an 

 hour and forty minutes in the same situation the 

 heat had fallen to 85, and when the bulb of the 

 thermometer was placed in the thorax in contact 

 with the lungs the mercury fell to 82. 



It has been the generally received opinion that 

 the heat of warm-blooded animals is dependent 

 on the chemical changes produced on the blood 

 by the air in respiration. In the two last experi- 

 ments the animals cooled very rapidly, notwith- 

 standing that the blood appeared to undergo 

 the usual changes in the lungs, and I was there- 

 fore induced to doubt whether the above men- 

 tioned opinion respecting the source of animal 

 heat is altogether correct. No positive con- 

 clusions, however, could be deduced from these 

 experiments. If animal heat depends on the 

 changes produced on the blood by the air in 

 respiration, its being kept up to the natural 

 standard must depend on there being a certain 

 quantity of air inspired, and a certain quantity of 



