Mifcellanea Guriofa. 239 



into It, by any the flighteft Force Imaginable. 

 It is true, the- Parts of Fire or Heat are not ca- 

 pable of moving them (elves any more than thofe 

 of Water, but they are more fubtil, light, and 

 a£Hve, than thole are, and fb more eafily put 

 into Motion. In fine, 'tis evident and matter of 

 Faci, that Heat does operate upon, and move 

 the Water, in order to its carrying on the Work 

 of Vegetation : But how 'tis agitated it /elf, and 

 where the Motion firft begins, this is no fit Place 

 to enquire. 



That the Concourfe of Heat in this Work 

 is really neceffary, appear?, not only from the 

 Experiments before uf, but from all Nature ; 

 from our Fields and Forefts, our Gardens and 

 our Orchards. We fee in Autumn, as the Sun's 

 Power grows gradually lefs and lefs, fb its Ef- 

 fects on Plants is remitted, and their Vegeta- 

 tion flackens by little and little. Its Failure 

 is firft difcernible in Trees. Thefe are raifed 

 higheft above the Earth ; and require a more 

 intenle Heat to elevate the Water, charged with 

 their Nourishment, to the Tops and Extre- 

 meties of them. So that for want of frefh 

 Support and Nutriment, they fhed their Leaves, 

 unlefs fecur'd by a very firm and hardy Con* 

 ftiturion indeed, as our cvcr-Greens are. Next 

 the Shrubs part with theirs ; and then the 

 Herbs and lower Tribes ; the Heat being at 

 length not fufficient to fupply even thefe, 

 though fb near the Earth, the Fund of their 

 Nourifliment. As the Heat returns the fuc- 

 ceeding Spring, they all recruit again ; and are 

 furnifh'd with frefti Supplies and Verdure: But 

 firft, thofe which are loweft and near eft the 

 Earth, Herbs, and they that require a leffer 



degree 



