( 2«7 ) 
CHAP. 1. 
Experiments^ fhevoing the ( 2 j*antity of Moifiure imhihd 
and perfpir'd hy Flants and Trees. 
O UR ^Author having cover’d with mill'd Lead a 
Garden-Pot, in wliich a Sun-flower was grow- 
ing, fo as to leave only one Pailage for Air ro commu- 
nicate with the Earth, and another to pour in Water 
to water the Plant, made ieveral curious Experiments 
upon it ; from the Obfervation of which it ap- 
pear’d, 
I. That the Plant, which weigh’d about 3to, per- 
fpir’d 30 Ounces in a 12 Hours Day, in the Month of 
July, 1714. But in a warm Night it perfpir’d only 
three Ounces, and nothing in a cold Night; nay, fome- 
times it gain’d Weight by imbibing Dew. 
2. That as the Area of the Surface of the Leaves 
was equal to ^616 fquare Inches, and the Area of the 
Roots only to 2286 fquare Inches; the Moiflure or 
Water imbib’d by the Roots to Tupply the Perfpiration 
at the Leaves mull: move farter in the Roots than thro* 
Leaves, in the Proportion of 5 to 2;* but in the Stem, 
whofe tranfverfe Section was one fqiiare Inch, farter 
thin in the Leaves, in the Proportion of 5616 
to r, 
3. That by comparing his Experiments made on 
this and other Sun-flowers and Plants, whth Dr. T’ei/s 
Experiments mention’d in the Medicina Statka Bri- 
tannka, it is evident, that a Man (Surface for Surface) 
perfpires more than a Plant, in the Proportion of 
3 i to I — • That the Quantity of the Food of a Man 
is to the Food of a Plant nearly as 7 to 2 ; but, 
Bulk for Bulk, the Plant imbibes into its VefTels 17 
times 
