226 



183. Mr Hunter, from whom the foregoing de 

 scription of the respiratory organs of birds is taken, 

 made several experiments upon the breathing of these 

 animals. He found, by making an opening into the 

 belly of a cock, and introducing a silver canula, pre- 

 viously to tying up the trachea, that the animal breath- 

 ed by this opening, and might have lived, but for an 

 inflammation of the bowels supervening, which, by 

 adhesion, cut off the communication with the air. 

 He next cut the wing through the os humeri, and, 

 tying up the trachea, found that the ait passed to and 

 from the lungs by the canal in this bone. The same 

 experiment was made with the os femoris of a 

 young hawk, and was attended with nearly the like 

 success : but the difficulty of breathing was greater 

 than in the former case, and the animal soon died *, 

 From the great size and peculiar communications of 

 the respiratory organs of birds, it may be presumed, 

 that, in proportion to their bulk, they respire a very 

 large quantity of air ; and accordingly, it has been 

 found by experiment, that, in a given time, they 

 consume more oxygen than other animals of the 

 same size, and therefore die sooner in a given vo- 

 lume of air. With regard to their temperature, Dr 

 Marrine found them to be warmer than quadrupeds 

 by three or four degrees : for the thermometer be- 

 ing lodged in the groin of ducks, geese, hens, 

 pigeons, partridges, swallows, &c. the mercury was 

 raised to 103, 104, 105, 106, and 107 : and, in 



* Observations on the Animal (Economy, p. 8L 



