372 BOAED OF AGEICULTURE. 



stimulating vegetable growth, would seem to show that it 

 may be successfully substituted under certain conditions. 

 His experiments led to the following conclusions : — 



1. That electric light is efficacious in producing chlorophyl 

 in the leaves of plants, and in promoting growth. 



2. That an electric centre of light equal to 1,400 candles, 

 placed at a distance of two meters from growing plants, ap- 

 peared to be equal in effect to average daylight at this season 

 of the year, but that more economical effects can be attained 

 by more powerful light-centres. 



3. That the carbonic and nitrogenous compounds generated 

 in diminutive quantities in the electric arc produce no sensi- 

 ble deleterious effects upon plants enclosed in the same 

 space. 



4. That plants do not appear to require a period of rest 

 during the twenty- four hours of the day, but make increased 

 and vigorous progress if subjected during daytime to sun- 

 light, and during the night to electric light. 



5. That the radiation of heat from powerful electric arcs 

 can be made available to counteract the effect of night-frost, 

 and is likely to promote the setting and ripening of fruit iu 

 the open air. 



6. That while under the influence of electric light, plants 

 can sustain increased stove-heat without collapsing, — a cir- 

 cumstance favorable to forcing by electric light. 



7. That the expense of electro-horticulture depends 

 mainly upon the cost of mechanical energy, and is very 

 moderate where natural sources of this energy, such as water- 

 falls, can be made available. 



As we look out upon our farms, let us call up before us 

 the W'Orking-forces Avhich are building up the plant-struc- 

 tures in our fields. If the day is one in midsummer, when 

 the sun shines brightly, and moisture exhales from the odor- 

 ous soil, we cannot avoid a feeling of exultation and wonder 

 as we gaze around us, so active and energetic are the forces 

 which are at work in building up cell upon cell in the grain 

 and grass plants. On such a day I have frequently turned 

 ray ear to listen, expecting to hear, and even imagining I 



