258 



Upon the rate of growth by Plants, 



On July 19th, there was a thunder storm in the morning, the 

 thermometer being 65^°. The growth of the experimental plants 

 on that occasion was as follows : 



So that on this occasion, when the atmosphere was highly 

 charged with electricity, five out of the seven experimental 

 plants grew considerably below the average rate, and of the others 

 one but little exceeded it. It might perhaps be supposed that the 

 influence of the thunder storm would be felt shortly before and 

 after its occurrence, rather than during its continuance ; but that 

 was not the fact. 



On the occasion in question the growths immediately before and 

 after the thunder storm were as follows : 



So that in every instance except one the average rate of growth 

 was diminished, instead of being increased, and the night growth of 

 the Fig was arrested altogether, an event which only happened on 

 six other occasions, and then under circumstances equally unintel- 

 ligible; on one of those occasions the thermometer was 58 j° with 

 rain ; on another 7H° and hazy. 



For the purpose of ascertaining the real effect of both high and 

 low temperatures, the following tables have been drawn out. 



