228 Mr, Livingjlon on the Effe^s of Shade, ^c, 



year, were drawn from chef nut trees (landing on the eajlfids 

 of a field of corn : this year, from thofe which grow on the 

 Tjoejl and [outh wefi fide of the buckwheat : This experiment 

 which I have made with attention under the mofl favourable 

 circumftances, as well with refped to the pofition of the trees, 

 the nature of the vegetable and the feafon of the year, have 

 confirmed me in the theory I hinted to you ; that the injury 

 which fome vegetables receive from the fhade of certain trees, 

 is not owing fimply to the diminution of light, but either to a 

 change the light undergoes in paffing through them, or from 

 its diflblving and becoming the vehicle of fome fubftance 

 noxious to certain plants contained in the tree, through which 

 it paffes. There are few fads in phyficks that do not admit 

 of fome ufeful dedudions ; I have taken pains to eftabhfh this, 

 that you, or fome other chymifl of more leifure and equal 

 information may make them. 



