DIFFERENT ANIMALS. 



563 



is so constructed that only a portion of blood is 

 sent through their imperfectly developed lungs, 

 we find that the power of obtaining caloric from 

 the air by respiration is small ; that their tem- 

 perature rises and falls with that of the surround- 

 ing medium, and rarely exceeds it more than a 

 few degrees in their most active condition ; while 

 in fishes, Crustacea, mollusca, annelida, and all 

 the more imperfect animals that live in water, 

 and breathe by means of branchiae or gills, it 

 is still less, as may be seen by referring to the 

 third Table. 



It was discovered by Lavoisier, more than fifty 

 years ago, that two sparrows confined in a vessel 

 of air generated more carbonic acid in a given 

 time than a young guinea pig under the same 

 circumstances. And it has been recently esti- 

 mated by Treviranus, from the experiments of 

 different physiologists, that for every 100 grains 

 weight of birds, they generate in 100 minutes 

 nearly twice as much carbonic acid as mam- 

 malia, and the latter above eight times more 

 than the frog, as may be observed in the ensuing 

 Table. (Muller's Elements, p. 312.) 



Oxygen consumed. Carbonic acid exhaled 



Cubic inch English. Cubic inch. 



Pigeon 1-14 0'96 



Ditto 1-58 0-99 



Guinea Pig 0-67 0-42 



Ditto 0-74 0-60 



Ditto 0-68 0-47 



Rabbit 0-60 0-44 



Cat 0-98 0.66 



Frog 0-00 0-06 



Allen and Pepys. 



Despretz. 



Berthollet. 



Allen and Pepys. 



Despretz. 



Berthollet. 



Despretz. 



Miiller and Treviranus. 



