670 PHILOSOPHICAL TRANSACTIONS. [aNNO 1712. 



covery was so evident, that on a little disturbing the glass that contained them, 

 they were actually in motion again : and at this time also, the fishes in the 

 water purged of air, began to appear more brisk and lively than at the last ob- 

 servation. Here I cannot but take notice, that though the water was purged 

 of its air to a very great degree, yet the fishes put into it did not so much as 

 once ascend in it; but continued always at the bottom, as those did in the 

 common water. At this time I left them till the next morning ; when, about 

 8 o'clock, I found them as lively in all the glasses, as when first put in. Those 

 in the common water exposed to the open air suffered no change during the 

 whole time. After this, wanting to try whether the air had again insinuated 

 itself into the exhausted water, and whether that might not be the cause of 

 the fishes recovery ; I put it on the plate of my pump, in the same glass with 

 the fishes in it ; and being covered with another receiver, the air was taken 

 from it; yet I could perceive very little air ascend in it, and to me it seemed to 

 be much in the same state as when the fishes were first put in. I continued it 

 in vacuo about an hour and half; the fishes almost all the time continued at 

 the top of the water, and at that time appeared as dead; for on admitting 

 the air, they sunk hastily to the bottom, without any motion of their fins 

 or tails. 



From the whole account I observe; 1st. That water purged of air, so far as 

 the method here made use of, is capable to do it, renders it not altogether unfit 

 to support the lives of water animals. For though when the fish were first put 

 in, and for some hours after, they seemed to suffer some uneasiness ; yet at 

 length the water became more familiar to them, or their constitutions in some 

 measure did so conform, as to render the water to them, and them to the water, 

 more agreeable: otherwise I do not see how their recovery should follow, since 

 on examination, little or no alteration could be found in the circumstances of 

 the water, from the time the fish were first put in. 



Odly. The fish included with their water from any communication with the 

 external air, plainly demonstrate, that common water in its natural state is not 

 alone sufficient to preserve the lives of its natural animals. Hence it follows, 

 that in ponds, when the water comes to be frozen over with a pretty thick ice, 

 the fish in such ponds are very likely, if not certain to perish, on the continu- 

 ance of such a congelation for some time on their surfaces ; unless (as in the 

 latter part of the experiments) the impediment, which hindered the immediate 

 contact of the air with the surface of the water, be removed; that is, by break- 

 ing holes in the ice, by which it is restored, and undoubtedly will perform the 

 wme thing as my removal of the brass plate. This is to be understood only in 



