282 ON WATER AND WATERING PLANTS. 



This he does not note, as a thing very considerable in itself, 

 but chiefly in regard to what he is to offer anon ; and that it may 

 be seen, that in other collations of things he has made due allow- 

 ance for this difference. 



Observation 2. The much greatest part of the fluid mass that is 

 first drawn off, and conveyed into the plants, does not settle or 

 abide there, but passes through the pores of them, and exhales 

 up into the atmosphere. 



It is certain that the water in these experiments ascended 

 only through the vessels of the plants. The glasses F and G 

 which had no plants in them, though they were disposed of in 

 the like manner as the rest were, remained at the end of the ex- 

 periment as at first, and none of the water was gone off: and it 

 is certain, that the greatest part of it flies off from the plant into 

 the atmosphere. 



" The least proportion of the water expended, was to the aug- 

 mentation of the plant, as forty-six or fifty to one ; and in some 

 the water drawn off was a hundred, two hundred, nay, in one 

 above seven hundred times as much as the plant had received of 

 additlion. 



This so continual an emission and detachment of water, in so 

 great plenty from the parts of plants affords a manifold reason 

 why those countries which abound with trees and the larger ve- 

 getables, especially, should be very obnoxious, owing to damps, 

 great humidity in the air, and more frequent rains than others 

 which are more open and free. 



The great moisture in the air was a mighty annoyance to those 

 who first settled in America, which then was much overgrown 

 with woods and groves ; but as they were burnt and destroyed 

 to make room for habitations and the culture of the earth, the 

 air mended, and cleared up apace, and became of a tempera- 

 ture much more dry and serene than before. 



Nor does this humidity go off pure and alone, but usually car- 

 ries out along with it many parts of the same nature, whereof 

 the plants, through which it passes, do consist. 



It is true, the crasser are not so easily born up into the atmos- 

 phere, but are usually deposited on the surface of the flowers, 

 leaves, and other parts of the plants. Hence are produced our 

 mannas, our honies, and other gummous excudations of vege- 

 tables. 



But the finer and lighter parts are, with so much the greatei 



