ELECTRICITY AND TLANT-GROWING. 67 



before the light started. The violets (Marie Louise) were all set 

 in the light liouse at twelve to sixteen feet from the lamp, where 

 they received the full benefit of the light. Half of the bed of one 

 hundred plants was covered each night with a black enamel-cloth 

 box, provision being made for ventilation, and the other half 

 received the light. Three weeks after the light started, the 

 exposed plants began to bloom, while no buds could be found in 

 the darkened portion. It was not until five weeks after the start- 

 ing of the light that a flower appeared in the darkened plants, 

 while the others had continued to bloom. Fifty strong plants of 

 the low daisy (Bellis perennis) were divided between the two 

 houses. Those in the light compartment were from fifteen to eigh- 

 teen feet from the lamp, in rather weak light. The first bloom 

 appeared just four weeks after the starting of the light, and it was 

 in the light house. For a month or six weeks thereafter the 

 lighted plants bloomed more profusely ; but at that time the dark 

 house plants began to surpass the others, both in numbers 

 and size of fiowers and vigor of plants. In other w^ords, the 

 lighted plants bloomed earlier and never made such stocky plants, 

 and they soon exhausted themselves. It is probable that they 

 would have endured longer if they had been established in the 

 beds for a longer period before the light was put upon them. 



In addition to all these plants, we have exposed many other 

 plants to the influence of the arc light with varying and interesting- 

 results. Of these, the most obstinate appear to be cucumbers, 

 tomatoes, and beans, none of which we have been able to persuade 

 to cast off the ways of their fathers ; but we are still hopeful that 

 they may respond to the attractions of the higher education ! 



I have already referred to the poor performance of caulifiowers 

 under the light ; and this introduces a subject which I have only 

 hinted at heretofore — the fact that the electric light often changes 

 the habit or method of growth of the plant. The light makes 

 cauliflowers grow tall, and draws the leaves up to a nearlv 

 vertical direction ; whilst plants in a normal house or far removed 

 from the light are lower and spread their leaves, at maturity, 

 nearly horizontally. Plants near the light are also lighter green 

 than others, and, contrary to other experience, they seem to be 

 somewhat later in heading. The difference in stature of plants at 

 distances of ten and fifty feet from the lamp was very marked, the 

 average heights at these respective points being as five is to three. 



