Volume 1

The works of John Hunter / edited by James F. Palmer.

Date:
1835-37
Catalogue details

Licence: Public Domain Mark

Credit: The works of John Hunter / edited by James F. Palmer. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    the thermometer between the thorax and pelvis. The mercury rose to 74|°, at the liver to 81^°. I put the mouse into an atmosphere at 30°, and when the hall was again introduced into the belly the mercury rose to 92°, at the liver 93°, the animal being still very lively. Here was an increase of 17^° in the belly, and llL° at the liver, and this produced by the application of cold to the skin. Of the Resistance to foreign Heat above the standard.—We have found that animals evidently possess a power within themselves of producing heat when in a cold atmosphere, so as to keep their bodies in a tempe- rature suitable to the ceconomy of the animal. But as animals are often placed in an atmosphere much hotter than their standard heat, I wanted next to see how far they have a cooling power, or, if they have not, to what degree the heat of an animal might he increased, and what might he the consequence of that increase, supposing it possible; for d priori we should suppose that the standard heat, or that heat at which all the animal functions are best carried on, would be the medium heat of the animal. But I find from experiment that the standard is generally within a degree or two of the ultimate heat that the animal can bear. As allowing the heat to rise above the standard could answer no wise purpose, Nature has put a check to it by making the stimulus of heat the cause of its own annihilation, just as the stimulus of cold produces, on the other hand, an increase of heat*. This would appear to take place in two different ways: one is by evaporation, which arises from the action of the living powers; and the other by an immediate power of destroying heat. So that animals have two means of destroying heat, while it would appear that they have only one for the production of it. I put a viper into an atmosphere at 108°, and allowed it to stay in seven minutes, when the heat in the stomach and anus was 92|°, beyond which it could not rise in the above heat. The same experiment was made on frogs with nearly the same success f. I now tried to what degree of heat I could bring a more perfect animal; and as I found the penis the best part for trying the experi- ment with cold, I imagined it would be the best for the trial of heat. The experiments were made in the same manner with the former, only * [The cause of animal heat is considered in the Treatise on Inflammation, Part II., chap, iii., sect. 3 ; and the mode by which the temperature is regulated, at sect. 4. The reader is referred to this part of the Work, as well as to the author’s paper on this sub- ject in Vol. IV.] f [According to De la Roche, the temperature of frogs docs not rise above 80° to 82° in a medium of 110° or 115°. (Journ. dc Fhys., tom. lxiii.)]