I 



34* 



Of Vegetation. 



We may plainly fee the influence of the 

 Sun's warmth in expanding the fap in all 

 the parts of vegetables, as well in the roots 

 as the body that is above ground, by the 

 influence it has on the fix Thermometers 

 defer ibed under Experiment 20, five of which 

 were fixed at different depths from two in. 

 ches, to two feet under ground, the other 

 being expofed to the open air. 



When in the greateft noon tide heat the 

 fpirit of that which was expofed to the Sun 

 was rifen, fince the early morning, from 21 

 to 48 degrees ; then the fpirit in the fecond 

 Thermometer •, whofe ball was two inches 

 under ground, was at 45 degrees, and the 

 3d, 4th, and 5th Thermometers were gradu- 

 ally of lefs and lefs degrees of heat, as they 

 were placed lower in the ground to the fixth 

 Thermometer, which was two feet under 

 ground, in which the fpirit was 3 1 degrees 

 high. In this flate of heat on all the parts 

 of the vegetable, we fee the Sun muft have 

 a very confiderable influence in expanding 

 the fap in all its parts. The warmth was 

 much greater on the body above ground, 

 than on the roots which were two feet deep 5 



thofe roots, and parts of roots which are 



deepeft, 



