224 M'" Living Jlon on the Effetts of Shadcy (B-c, 



as the fliade of the chefnut reached, the corn was extremely 

 injured ; it was yellow and fmall \ the conical fliape of the 

 morning fiiade from particular trees, might be traced a 

 confiderable extent, in the fickly appearance of the plants ; 

 the black oaks were likewife injurious, but lefs fo than the 

 chefnut ; the poplars very little fo.— Near the mulberry tree, 

 the corn was covered by its lliade for a very long time every 

 morning, and tho' not fo large as that which had more fun, 

 maintained a healthy appearance. . To what caufe are v^'e to 

 attribute this phEsnomenon ? it is certainly not the mere 

 ahfence oj light or heat ; for in this cafe the trees would have 

 been equally injurious, or rather the mulberry would have 

 been moil So, It is not to any dropping from the trees ; 

 for the corn grew under none but the mulberry. It is not to 

 any ej^.uvia from .the trees; for this would either be emitted 

 m circles, or wafted irregularly by the wind ; whereas the 

 ihape of the ffiade was plainly traced upon the corn. Were I 

 permitted to form a conjefture upon this extraordinary 

 circumftance, I fliould conclude, that the mifchief v^^as not 

 occafioned by the Jbade^ but by thofe rays of light that aClually 

 palled through the tree, either perforating the leaves (for none 

 of them are perfeftly opake) or being brought into contaB with 

 them ; and that this light ferved as a menftruum, to diflblve 

 certain parts of the tree noxious to corn, and as a vehicle to 

 convey it in the direction of the rays (which neceflarily are 

 that of the fhadc) As the injury is done in the line in -^'hich 



