294 Influence of Electric Light upon Vegetation. [Mar. 18, 



be accelerated by the same agency, but proof thereof was then want- 

 ing. A continuation of my experiments has furnished interesting 

 evidence that the electric arc is also efficacious in hastening the 

 ripening process in strawberries, and probably in nearly every descrip- 

 tion of fruit. 



Several plants of early strawberries in pots were divided as before 

 into two groups, the one to be subjected to the action of daylight only, 

 and the other to solar light during the day time, and to electric light 

 during the night. Both groups of plants were placed below glass at 

 temperatures varying from 65° to 70° F., but those that were to receive 

 daylight only were shielded from the effect of the electric light during 

 the night by matting. 



At the commencement of the experiment the strawberry plants 

 selected were just setting fruit, being still partly in bloom. After 

 eight days the fruit on the plants exposed to electric light had swelled 

 very much more than on the others, some of the berries beginning to 

 show signs of ripening. The experiment was interrupted for two 

 nights at this stage, but after the electric light was resumed, very 

 rapid progress towards ripening was observable ; so that with four 

 days' continuous exposure to both day and electric light, the greater 

 number of the berries had attained to ripeness, and presented a rich 

 colouring, while the fruit on those plants that had been exposed to 

 daylight only had by this time scarcely begun to show even a sign of 

 redness, 



This experiment goes to show that the electric light is very effica- 

 cious in promoting the formation of the saccharine and aromatic 

 matter upon which the ripening and flavour of fruit depends ; and 

 if experience should confirm this result, the horticulturist will have 

 the means of making himself practically independent of solar light 

 for producing a high quality of fruit at all seasons of the year. 



Two strawberry plants are placed before the meeting illustrative of 

 the result here described. 



Although I have shown that in employing a lamp of 1,400 candle- 

 power a distance of 3 metres produces a maximum beneficial 

 result on vegetation, the effect is nevertheless very marked upon 

 plants at greater distances. This influence at a distance was illus- 

 trated in my experiments by the condition of three melon plants 

 towards the back of the house, which throve remarkably well for a 

 period of about a fortnight, during which the electric light was 

 placed in front of the house, at a distance of from 5 to 6 metres from 

 the plants. The electric light was then removed in front of the other 

 end of the same house, thus depriving the plants in question of its 

 influence, since which time they have continued their growth, but 

 show a very decided falling off in size and colouring of the leaves that 

 have since formed. 



