CONSUMED BY ANIMALS. 35 



been equally unsatisfactory. Animals have been al- 

 lowed to respire in close chambers surrounded with 

 cold water ; the increase of temperature in the water 

 has been measured by the thermometer, and the quan- 

 tity of oxygen consumed has been calculated from the 

 analysis of the air before and after the experiment. In 

 experiments thus conducted, it has been found that the 

 animal lost about ^ more heat than corresponded to the 

 oxygen consumed ; and had the windpipe of the animal 

 been tied, the strange result would have been obtained 

 of a rise in the temperature of the water without any 

 consumption of oxygen. The animal was at the tem- 

 perature of 98 or 99, and the water, in the experi- 

 ments of Despretz, was at 47*5. Such experiments 

 consequently prove, that when a great difference exists 

 between the temperature of the animal body and that 

 of the surrounding medium, and when no motion is al- 

 lowed, more heat is given off than corresponds to the 

 oxygen consumed. In equal times, with free and un- 

 impeded motion, a much larger quantity of oxygen 

 would be consumed without a perceptible increase in 

 the amount of heat lost. The cause of these phenom- 

 ena is obvious. They appear naturally both in man and 

 animals at certain seasons of the year, and we say in 

 such cases that we are freezing, or experience the sen- 

 sation of cold. It is plain, that if we were to clothe a 

 man in a metallic dress, and tie up his hands and feet, 

 the loss of heat, for the same consumption of oxygen, 

 would be far greater than if we were to wrap him up in 

 fur and woollen cloth. Nay, in the latter case, we 



