86 MK. SOLLY ON THE 



same year a naturalist in London determined to repeat the ori- 

 ginal experiment of Dr. Maimbray,* and accordingly electrified 

 a myrtle for many hours a day for some time, in the middle of 

 December ; the result was that the tree formed buds, and threw 

 out small branches in a very remarkable manner. 



Dr. Marat described in 1782t some experiments which he had 

 made on the germination of electrified seeds ; from which he 

 draws the conclusion that it exerts powerful influence on the fer- 

 tility of the soil. Six porcelain vessels filled with moist earth, 

 and each containing lettuce seed, were prepared in all respects 

 alike ; three were placed in a very large glass jar well insulated, 

 whilst the others were placed in an adjoining room also insulated. 

 The temperature in both rooms being two degrees above the freez- 

 ing point, and all other circumstances alike, the jar was kept con- 

 stantly electrified seventeen hours a day for a fortnight. On the 

 seventh day the plants began to make their appearance in the 

 electrified vessels ; and at the end of the fortnight they were as 

 forward as similar plants sown on the same day, but kept in a 

 room nine degrees above the freezing point. In the three 

 vessels which were not electrified the seeds had not begun to 

 germinate. 



The next important addition to our knowledge of the 

 electricity of vegetation was by the Abbe Bertholon. This 

 philosopher having paid much attention to the subject, and 

 made numerous experiments, published the results of his in- 

 quiries in his book ' De I'Electricite des Vegetaux.'| The first 

 subject treated of in this work is the influence of atmospheric 

 electricity upon growing plants, which the author endeavours 

 to prove in various ways : first showing the constant presence 

 of free electricity in the air, he proceeds to argue that so 

 powerful an agent must produce some efi^ect upon plants, and 

 then goes on to describe the eflPects which are produced by 

 lightning and other phenomena of atmospheric electricity. In 

 these chapters the influence of electricity on the general produc- 

 tiveness of crops is asserted, and several remarkable instances are 

 adduced in confirmation of the author's views: thus, for example, 

 he states, on the authority of M. Vyssery, that in the year 1780 

 the hops failed in certain districts, and it was observed that there 

 was very little lightning ; whilst in the following year there was 

 an excellent crop, and lightning was remarkably abundant : 

 many other statements of a similar nature are also given. The 

 great conducting power of water, its presence in the atmosphere, 



♦ La Nature consideree, p. 89. 



t Recherches Physiques sur I'Electricite, p. 359. , 



j Paris, 1783, 8yo, 



