270 HISTORY OF 



ever, that do not require their needful supply. 

 Fishes themselves will not live in water from 

 whence the air is exhausted ; and it is generally 

 supposed that they die in frozen ponds, from the 

 want of this necessary to animal existence. Many 

 have been the animals that idle curiosity has tor- 

 tured in the prison of a receiver, merely to ob- 

 serve the manner of their dying. We shall, from 

 a thousand instances, produce that of the viper, 

 as it is known to be one of the most vivacious 

 reptiles in the world, and as we shall feel but 

 little compassion for its tortures. Mr Boyle took 

 a new-caught viper, and shutting it up into a 

 small receiver, began to pump away the air.* 

 '* At first, upon the air's being drawn away, it 

 began to swell; some time after he had done 

 pumping, it began to gape, and open its jaws ; 

 being thus compelled to open its jaws, it once 

 more resumed its former lankness ; it then began 

 to move up and down within, as if to seek for 

 air, and after a while foamed a little, leaving the 

 foam sticking to the inside of the glass ; soon after 

 the body and neck grew prodigiously tumid, and 

 a blister appeared upon its back ; an hour and a 

 half after the receiver was exhausted, the distend- 

 ed viper moved, and gave manifest signs of life ; 

 the jaws remained quite distended; as it were from 

 beneath the epiglottis, came the black tongue, 

 and reached beyond it ; but the animal seemed, 

 by its posture, not to have any life : the mouth 

 also was grown blackish within ; and in this situa- 



* Boyle's Physico- Median. Exper. 



