217 



1 75. The class of fishes possesses also a temperature 

 above that of the medium they inhabit. In floun- 

 ders, whitings, cod-fish, and haddocks, the tempera- 

 ture, according to Dr Martine, was scarcely a degree 

 more than that of the water they were swimming in, 

 even when that was so low as 41. Nor are the 

 red-blooded fishes much warmer than the white ones; 

 for trouts were but 62, when the river water 

 they were swimming in was 61; and carp and 

 eels hardly exceeded the heat of the water they 

 inhabited *. Mr Hunter, however, found the mer- 

 cury in the thermometer to stand at 69 in the 

 stomach of a carp, when the water in the pond 

 from which he was taken, was only 65.5. That 

 fishes part with this excess of heat to the cold- 

 er bodies which surround them, we learn also from 

 the experiments of the same author. He put two 

 carp into a glass-vessel with common river water, 

 and then placed the vessel in a freezing mixture : 

 and, as the water in the vessel did not freeze fast e- 

 nough, snow was added so as to render the whole 

 thick. The snow round the carp melted, and more 

 being added, it melted also, till at last he grew tired 

 of putting it in, and left them to freeze by the 

 joint operation of the freezing mixture, and the 

 natural cold of the atmosphere. At length they 

 froze, but did not, when thawed, recover life with 

 flexibility f ; but, that both snakes and fishes, after 

 being frozen, have still retained so much of life, as 



* On Thermometers, p. 141. 



f Observations OH the Animal (Economy, p. 89. 



