492 PHILOSOPHICAL TRANSACTIONS. [aNNO I67O. 



be much more lively than was expected, which may in part be attributed to a 

 little air that by an accident got in, though it was immediately pumped out 

 again. At the end of a full quarter of an hour from the first exhaustion of the 

 receiver, the bird appearing not likely to die in a great while, and the engine 

 being needed for other uses, we took out the bird, and thereby put a period to 

 the experiment. 



Eccp. V. — April 12. I now thought fit to try whether, though a viper would 

 not hold out very many hours in air brought to as high a rarefaction as we could 

 bring it by our engine, yet to that cold and vivacious animal, a very small pro- 

 portion of air, in comparison of what was necessary to hot animals, would not 

 suffice to keep it alive for a considerable time. 



A viper lately taken was included, together with a gauge, in a portable receiver, 

 capable of holding about 3-|- pints of water. This vessel being exhausted, and 

 secured against the regress of the air, the imprisoned animal was observed 

 from time to time nimbly to put out and to draw back its tongue about 36 

 hours after it was first shut up, for which reason we continued the vessel longer 

 in the same shady place, where at the end of 6o hours looking upon her, as I 

 was going to bed, she appeared very dull and faint, and not likely to live much 

 longer; and the next morning being by some occasions carried abroad, and com- 

 ing to look upon the glass presently after dinner, I found her stark dead, with 

 her mouth opened to a strange wideness ; wherefore suffering water to be im- 

 pelled by the outward air into the cavity of the receiver, to observe how far that 

 vessel was then emptied of air, we found by the water that was driven in, and 

 afterwards poured out again and measured, that four parts of five, or rather five 

 of six of the vesseled air, (if I may so call that which was shut up in the re- 

 ceiver) had been pumped out; so that in an air so rarefied as to expand itself to 

 five or six times its former and usual dimensions, our viper was able to live 6o 

 hours, that we are sure of, and perhaps might a pretty while longer. 



A digressive Experiment concerning Respiration upon very high Mountains. 

 To illustrate what I have taken notice of in the printed experiments about the 

 imfitness for respiration observed by the learned Acosta in the high mountains 

 of Pariacacha, I shall here add what I have had the curiosity to learn from divers 

 travellers, whom I purposely consulted about these matters; whereof you will 

 easily believe that not many of them have had opportunity to give accounts. 

 Meeting with an ecclesiastical pers6n that had visited those high mountains of 

 Armenia, (on one of which, because of their height, the tradition of the na- 

 tives will needs have the ark to have rested) I asked him whether those moun- 

 tains are really so high as is given out, and whether at the top of that he visited 



