Chap. ip. ATyedifi tf BODIES. 211 



main predominance and reigneth moil continually, as near the 

 Jcafliorc upon the weftcrn coaft of England(whcrc the fbuth weft 

 wind bkweth conftantly the greatelt part ofchcyeare) may be 

 obierred: but this effcil proceeding from a particular and extra- 

 ordinary caule, conccrneth not our matter in hand. 



We are to examine the reafon of the morion ofReftitution, 

 \vhich we generally iec in young trees, and branches of others., 

 as we laid beforeJn fuch,we fee that the earthy part which mak- 

 eth them iliffc (or rather (lark) a bound eth more in them then in 

 the others that ftand as they are bent: <at dvc leaft in proportion 

 to their natures ; but I conceive this is not the caufe of the effect 

 We enquire about;but that it is a fubtiic fpirit which hath a great 

 proportion of fire in it. For as in rarefaftion, \\efound that fire, 

 which was either within or without the body to be ranfyed, did 

 caufe the rarefaction, either by entering into it, or by working 

 within it:fo feeing here the queftion is, for a body to go out of a 

 lefier fuperficies into a greater (which is the progrefle of rarefa- 

 dion;and hapneth in the motion of rettitution; ) the work tnuft 

 needs be done by the force of heat. And becaufe this effect pro- 

 ceedeth evidently, out of the nature of the thing in which it is 

 wrought, and not from any outward caule, we may conclude ic 

 hath its origine from a heat that is within the thing it felfjor elfe 

 that was in it, and may be prcfled to the outward parts of it,and 

 Would fink into it again. 



As for example* when a young tree is bended both every 

 mans conceit is, and the nature of the thing maketh us believe, 

 that the force which bringcth the tree back again to its figure, 

 corneth from the inner fide that is bent; which is compreffed to- 

 gether,as being fhrunk into a circular figure from a ftraight one: 

 for when fblide bodies that were plain on both fides, are bent fo 

 as on each fide to make a portion of a circle, the convex fuperfi- 

 cies will be longer then it was before, when it was plain, but the 

 concave will be fliortcr. And therefore we may conceive that the 

 fpirits which are in the contracted part, ( being there Iqueezcd 

 into JelTe room, then their nature well brookethjdo work thern- 

 felves into a greater fpace; or elfe that the fpirits which arecrufh- 

 edout of the convex fide by the extenfion of it, but do remain 

 bcfieging it,and do ftrive to get in again,(in fuch manner as we 

 ha-ve declared when we fpokc of attraction, wherein we flic wed 



O 2 how 



