390 NOVUM O RCA NUM. 



annihilation, Art prevents also the loss or escape of any part. On 

 this subject there has prevailed a false opinion, which, if true, would 

 well nigh render desperate our chance of preserving a fixed quantity 

 without diminution, viz., that spirits of bodies, and air when rarefied 

 by a high degree of heat, cannot be contained in closed vessels, but 

 escape through their more delicate pores. To this opinion men have 

 been led by the common experiment of a cup inverted over water, 

 with a candle or a piece of paper lighted inside it ; the consequence of 

 which is that the water is drawn up : and by the familar experiment of 

 cupping-glasses, which, when heated over flame, draw up the flesh. 

 For Ithey think that in each of these experiments the rarefied air 

 escapes, and that its quantity being thereby diminished, the water or 

 flesh takes its place by Motion of Connection. But this is most 

 erroneous. For the air is not diminished in quantity, but contracted 

 in space ; nor does the motion of the rising of the water begin till the 

 flame is extinguished, or the air cooled ; so that physicians, to make 

 their cupping-glasses draw better, place upon them cold sponges 

 moistened with water. Therefore there is no reason why men should 

 be much afraid of the easy escape of air or spirits. For though it be 

 true that even the most solid bodies have pores, still air or spirit with 

 difficulty endures such excessive subdivision ; just as water refuses to 

 run out at very small chinks. 



2. Concerning the second of the seven above-mentioned modes of 

 operating, we must especially observe, that compression and such 

 violent means have indeed a most powerful effect with respect to local 

 motion and the like, as in machines and projectiles, even to the 

 destruction of organic bodies, and of such virtues as consist entirely 

 in motion. For all life, nay, even all flame and ignition, is destroyed 

 by compression, just as every machine is spoiled and thrown into con 

 fusion by the same. It also leads to the destruction of those virtues 

 which consist in the position and the grosser dissimilarity of the parts. 

 This is the case with colours : for the whole flower has not the same 

 colour as when it is bruised ; nor the whole piece of amber as the 

 same piece pulverized. So also it is with tastes (for there is not the 

 same taste in an unripe pear as there is in a pressed and ripened one, 

 for the latter is decidedly sweeter). But this kind of violence has not 

 much effect on the more noble transformations and alterations of 

 similar bodies, because bodies do not acquire by them any new con 

 stant and quiescent consistency, but only one which is transitory, and 

 struggles always to restore and liberate itself. But it would not be 

 out of our way to make some rather careful experiments on this 

 matter : to see, that is, whether the condensation or rarefaction of some 

 very similar body (such as air, water, oil, and the like), being induced 

 by violence, can be made to be constant and free, and to become a 

 sort of Nature. Experiment should first be made by simple continu 

 ance, and afterwards by means of aids and sympathies. And this 

 experiment might have readily been made (if only it had occurred to 

 us) when we were condensing water (as mentioned elsewhere) by 

 means of hammering and compression, before it broke loose. For 



