PHENOMENA OF THE UNIVERSE. 145 



eighty fold to a body of water. The bladder filled with 

 wind in the manner I have mentioned, if no breathing place 

 be given, but it be removed whole from the fire, imme 

 diately decreases from the inflation and subsides and is 

 contracted. The vapour whilst the bladder swells, being 

 emitted from the hole, had another kind of vapour distinct 

 from the common one of water more thin, clear, and up 

 right, and not so soon mingling itself with the air. 



CAUTIONS. 



We must not suppose that if there were a greater con 

 sumption of water, a greater bladder could be filled in 

 proportion. I tried this and found that it would not 

 answer, but the inflation that follows upon it does not take 

 place gradually but altogether. This I attribute partly to 

 the inflaming of the bladder which was made harder and 

 would not yield so easily, and was perhaps more porous (but 

 this might be corrected by a moist heat as by the balneum 

 Maria) ; but still more to this, that the vapour being in 

 creased through the constant succession, inclines to recover 

 itself and condenses itself. The vapour, therefore, which 

 is received into the bladder is not to be compared to those 

 which are received into stoves, because these latter mutually 

 following and urging each other, thicken, but those expand 

 themselves at will from the soft and yielding nature of the 

 bladder, especially at the beginning (as I said), before the 

 copiousness of the vapour brings on its recovery. 



The expansion of the vapour of water is not to be judged 

 entirely from the appearance of the vapourwhich flies ofFinto 

 the air; for that vapour being immediately mixed with the air 

 borrows by far the greatest dimension of its mixed body from 

 the air, and does not remain in its own size. And so it is am 

 plified to the bulk of the air into which it is received, as a little 

 red wine or any other coloured fluid which imparts a colour 

 to a great quantity of water. The exact ratios in so minute 

 a case cannot be obtained without laborious and unprofit 

 able research, and are very slightly connected with our 

 present design. It is enough that from this experiment it 

 is plain that the ratio of vapour to water is not twofold, 

 nor tenfold, nor fortyfold, nor again a thousandfold, two 

 hundredfold, &c. For the limits, not degrees of natures, 

 are the subjects of our investigation. If, therefore, any 

 one, by any accident or slight variation in the mode of his 

 experiment, whether from the shape of the glass he makes 

 use of, or the hardness or softness of the bladder, or the 



VOL. XV. L 



