VOL. v.] PHILOSOPHICAL TBANSACTIONS. 483 



Exp. III. — Buf I thought it not unlikely, that there may be some such in- 

 equality in the strength or vivacity of animals, as to such kind of experiments ag 

 ours, that it might be worth while in several cases to repeat our trials. And on 

 this occasion I shall here add, that having put an oyster into a phial full of wa- 

 ter, before we included it in the receiver, that through the liquor the motion of 

 the bubbles, expected from the fish, might be the more pleasantly seen and 

 considered, this oyster proved so strong as to keep itself close shut, and repressed 

 the eruption of the bubbles, which in the other forced open the shells from 

 time to time; and kept in its own air as long as we had occasion to continue 

 the trials. 



Exp. IF". — Moreover a crawfish, that was thought more vigorous, being sub- 

 stituted in the place of the former crawfish, though once he seemed to lose his 

 motion together with the air, yet afterwards continued moving in the receiver, 

 in spite of our pumping: whether because there was some unperceived leaking 

 that hindered a sufficient exhaustion of the air, or because this particular ani- 

 mal was more strong or vivid than the other, we could not positively deter- 

 mine. 



The Seventh Title. 

 Of the Phienomena of a Scale Fish in an Exhausted Receiver. 



The following experiment is far from being the first that was made on a scale 

 fish in our vacuum ; but in regard that the receivers wherein those trials were 

 made, the external air could not be kept out so long and so well as in the ves- 

 sel I am about to mention, I judged it well worth the pains to obsen^e what 

 would happen to a fish in an exhausted vessel, where it should be kept for some 

 hours together from all supply of fresh air. And therefore I made several trials 

 to that purpose, whereof, that which I think the most considerable, was regis- 

 tered as follows : 



We took a receiver shaped almost like a bolt-head, containing by estimation 

 near a pint, and the globulous part of it being almost half full of water, we put 

 into it at the orifice (which was pretty large) a small gudgeon, about three inches 

 long, which, when it was in the water, swam nimbly up and down therein. 

 Then having drawn out the air so well that we guessed by a gauge that about 

 nineteen parts of twenty or more might be exhausted, we took care that the re- 

 gress of the air should not injure our experiment, about which we obser\ed these 

 particulars. 



1st. The neck of the glass being very long, though there appeared great 

 store of bubbles all about the fish, yet the rest of the water, notwithstanding 



3 p2 



