Chap, 17. ^rrrM///^/BODIES. 181 



be convinced by the contrary effect from a contrary caufe : for 

 take a bladder itrctched out unto ks greateft extent by aire (hut 

 up within it; and hang it in a cold placejand you will fee ic pre- 

 fently contract it felr'imo a lefle roome ; and the bladder will 

 grow wrinckled and become too big for the aire within it. But 

 tor immediate proof of this pofitioi^we fee that the addition of a 

 very fmall degree of heat, rarifieth the aire in a weather-glade, 

 fthe aire receiving the imprcflion ofheat,fooner then water) ind 

 fo makcth it extend it felf into a greater place; and consequently, 

 ic preflerh upon tV water; and forceth it down inroalefle 

 roomc then formerly it poflcffed. And likewile we fee quickfil- 

 ver and other liquors, if they be fhut up in glaOes clofe flopped 

 and fet in fufficient heac ( and a little is fuffieient for this effect ) 

 they will (well and fill their glaflcs ; and at the laft break them, 

 rather then no: find a way to give themfelves more roome ; 

 tthich is then grown too ftraight in the glaffe, by reafon of the 

 rarefaction of the liquors by the fire working upon them. 



Now again ; that this effect may be wrought by the inward 

 heat, that is enclofed in the bowels of the fubftance thus (hut up; 

 both reafon and experience do aflure us : for, they teach us that 

 if a body which is not extremely compacted, but that by ics 

 Joofenefle is eafily divifiblc into little parts (Yiich a oneas wine, 

 or other fpirituall liquors) be inclofed in a vcffell ; the little a- 

 tomes that perpetually move up and down in every fpace of the 

 whole world, making their way through every body, will fet on 

 \\ork the little parts,in the wine for cxample,to play their game : 

 fo that the hot and light parts^if chey be many)"not enduring to 

 be comprefled and kept in by the heavie and cold ones, do (eek 

 to break out with force ; and till they can fiee them/elves front 

 the denfe ones that would imprifon them they carry them along 

 \vi:h them, and make them to fwell o'lt as well as themfelves. 



Now if they be kept in by the yeflell, fo that they hive not 

 play enough;they drive the denfe ones (like fo many lirtle ham- 

 mers or wedges)igainft the fides ofit,and at the length dob"eak 

 it,and fo do make themfelves w ay,to a larger roome. But if they 

 have vent, the more fiery hot fpirits fly away, & leaye the other 

 grofTer parts quiet and at reft. On the other fide if the hot and 

 light parts in a liquor be not miny nor very adivc, and the 

 Ycflell be fa full that the parts have not frcefcopc to remove 



M and 



