476 PHILOSOPHICAL TRANSACTIONS. [aNNO I67O, 



me also to make several upon frogs ; the success of some of which, the follow- 

 ing notes will declare. 



Exp. I. — We took a large lusty frog, and having included her in a small 

 receiver, we drew out the air, and left her not very much swelled, and able to 

 move her throat from time to time, though not so fast as when she freely 

 breathed before the exsuction of the air. She continued alive about two hours, 

 that we took notice of, sometimes removing from the one side of the receiver 

 to the other ; but she swelled more than before, and did not appear by any 

 motion of her throat or thorax to exercise respiration, but her head was not 

 very much swelled, nor her mouth forced open. After she had remained 

 there somewhat above three hours, perceiving no sign of life in her, we let in 

 the air upon her, at which the tumid body shrunk very much, but seemed 

 not to have any other change wrought in it ; and though we took her out of 

 the receiver, yet in the free air itself, she continued to appearance dead. 

 Nevertheless to see the utmost of the experiment, having caused her to be 

 laid upon the grass in a garden all night, the next morning we found her per- 

 fectly alive again. 



Exp. II. — June 29, 1660. About ]1 of the clock in the forenoon, we 

 put a frog into a small receiver, containing about 15 J- ounces, troy weight of 

 water, out of which we had tolerably well drawn the air, (so that when we 

 turned the cock under water, it sucked in about 1 3^^ ounces of water,) the 

 frog continued in it (the receiver all the while under water) lively enough till 

 about five of the clock in the afternoon, when it expired. The frog at first 

 seemed to be not much altered by the exsuction of the air, but continued 

 breathing both with her throat and lungs. 



Exp. III. — Sept. 6, 1662. We included in a pretty large receiver a couple 

 of frogs newly taken, the one not above an inch long, and proportionally slen- 

 der, the other very large. Whilst the air was drawing out, the lesser frog 

 skipped up and down very lively, and clambered up several times to the sides 

 of the receiver, insomuch that he sometimes rested himself against the side 

 of the glass. When his body seemed to be perpendicular to the horizon, if 

 not in a reclining posture, he continued to skip up and down a while after the 

 exsuction of the air, but within a quarter of an hour we perceived him to lie 

 dead with his belly upwards. The other frog, that was very large and strong, 

 though he began to swell much upon the withdrawing of the air, and seemed 

 to be distressed by his frequently leaping up after the air was drawn out, which 

 he did not before, yet held out half an hour, at which time it was remarkable 

 that the receiver, though it had held out against the pressure of the outward 

 air, during that space of time, notwithstanding that a piece of it had been 



