Of Vegetation. 325 



the leaves feem alfo defigned for many other 

 noble and important fervices ; for Nature 

 admirably adapts her iufrruments fo as to 

 be at the fame time ferviceable to many 

 good purpoies. Thus the leaves, in which 

 are the main excretory duels in Vegetables, 

 feparate and carry off the redundant watry 

 fluid, which by being long detained, would 

 turn rancid and prejudicious to the plant, 

 leaving the more nutritive parts to coalefce ; 

 part of which nourishment, we have good 

 reafon to think, is conveyed into Vegetables 

 through the leaves, which do plentifully im- 

 bibe the dew and rain, which contain fait, 

 fulphur, &c. For the air is full of acid 

 and fulphureous particles, which when they 

 abound much, do, by the action and. re-action 

 between them and the elaftick air, caufe that 

 fultry heat, which ulually ends in lightning 

 and thunder : And thefe new combinations 

 of air, fulphur, and acid fpirit, which are 

 conftantly forming in the air, are doubtlefs 

 very ferviceable in promoting the work of 

 Vegetation ; when being imbibed by the 

 leaves, they may not improbably be the 

 materials out of which the more fubtile and 

 refined principles of Vegetables are formed : 

 For fo fine a fluid as the air feems to be a 



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