159. Electricity applied to the growth of Plants. 



tion is that of Pappi which have a special office for con- 

 veyance of seeds. Gardeners put metallic hoops over 

 frwting Melons which tend to take off electricity as well as 

 to shade them. 



4° Mr. Sidney asked whether there are not natural phe- 

 nomena tending to confirm these views! Vines ano Hops 

 are said to grow rapidly during and after a thunder storm, 

 and peas are found to pod after a tempest. If this effect 

 upon hops should hy some be ascribe 1 to the destruction of 

 Aphides, etc., by the lightning, it can be answered, that 

 these animals are so tenacious of life, that the very storm 

 which destroys the parasitic insect, would also injure, if not 

 kill the plants which fed it. Again, it is observed, that 

 where ever Simooms occur, which are generated by a high- 

 ly electrical state of the atmosphere, no plants occur, or 

 flourish. 



Mr. Brydone's observations of the presence of electricity 

 in the atmosphere of Mount OEtna in places where vegeta- 

 tion was absent, and its deficiency wherever vegetation 

 luxuriated, also indicates the influence of plants in distri- 

 buting electricity. This was illustrated by an experiment 

 with a cone of chalk with a piece of Moss on one part; the 

 part without the Moss brought near the machine, only 

 slightly affected the Electrometer, the Moss carried off the 

 electricity entirely. 



5° Mr. Sidney suggested the enquiry, whether the forms 

 and geographical distribution of certain species of plants, 

 did non indicate design with reference to their electrical 

 properties and uses. The prevalence of the Fir tribe in 

 high latitudes was n<ted; these trees are characterized by 

 their needle-shaped foliage, and it was argued that the con- 

 ducting power with which this form invested them, might 



