370 M E M O 1 R S of the 
end; upon the immeHion of which into the water, this by little 
and little alcended quite to the upper orifice of the tube 5 and 
\et in all the 56 days it thus flood, a very inconfiderable quantity 
of water had gone off, fcarcely 20 grains, tho' the fand continued 
moift up to the top to the very laft day 5 the water had imparted 
a green tinfiure to the fand, quite to the very top of the tube, 
and in the phial it had precipitated a grcenifh fediment mixed 
with black; pretty much of the green iubftance delcribed above 
adhered to the bottom and fides of the tube, as far as it was im- 
merfed in the water : (T R. S, ^c. are feveral plants fet in phials, 
ordered in like manner as thofe above in OBober, and the follow- 
ing colder months 5 thefe did not thrive near fo much, nor did 
the water afcend in near the quantity it did in the hotter leafbns, 
when the above trials were made. 
Upon thefe experiments the Do£lor makes the following re- 
flexions. I. In plants of the fame kind, the lefs they are in 
bulk, the fmallcr quantity of the fluid mals m which they are 
let, is drawn off; the expence, or wafting of it, where the 
mafs is of equal thicknefs, being pretty nearly proportioned to 
the bulk of the plant; thus that in the glals marked A, which 
weigh'd only 27 grains, drew off but 2558 grains of the fluid^ 
and that in B, which weighed only 28^, took up but 3004 
grains, whereas that in H which weighed 127 grains, Ipent 
14190 grains of the liquid mais: The water leems to afcend up 
in the veffels of plants in much the iame manner as up a filtre, 
fo that as a large filtre draws off more water than a lefTer, juft fo 
a plant, that has more and larger vellels, takes up a greater ihare 
of the fluid in which it is fet, than one that has fewer and fmal- 
ler ones can do. 
2. The much greateft part of the fluid mafs, that is thus drawn 
off, and conveyed into plants, does not fettle nor abide there, but 
paf[es thro' their pores, and is exhaled up into the atmolphere: 
The leaft proportion of water expended was to the encreafe of 
the plant, as 45 or 50 to i ; and in lome the weight of the water 
drawn off was ico, 200, nay, in one above 7C0 times as much, as 
the plant had been augmented in its growth : This lb continual an 
emilfion and detachment of water in ib great plenty from the parts 
of plants, affords us a manifefl reafon, why countries that abound 
in trees, and eipecially the larger vegetables, fhould be very ob- 
noxious to damps, great humidity in the air, and more frequent 
rains, than others that are more open and free ; nor does this 
moifture go off pure and alone, but ufually carries away with it 
Icveral parts of the lame nature, with thole whereof the plant 
thro' 
