i88i.] THE ELECTRIC LIGHT. 293 



during tlie northern winter, and the absence of heat, — any of which 

 would go a long way to account for the results of the northern summer, 

 without entirely giving the continuous light of the summer the credit 

 of them. 



3. The application of continuous light — that is, solar followed on by 

 electric light — however applied, whether outside or inside during the 

 low temperatures of soil and of atmosphere, of our winter months, 

 is not likely to be productive of high-coloured flowers, and of fruit with 

 high aroma. 



4. Again, as to the statement that electric light produces green col- 

 ouring matter in chlorophyll corpuscles, that may, or may not, be cor- 

 rect ; but in any experiments made after the absence of solar light with 

 the electric light, who is to decide whether the green colouring matter 

 is not due to the action of solar light during the daytime, rather than 

 to the action of electric light during darkness 1 Here I would remark 

 that chlorophyll is not now considered to have any power to decompose 

 carbonic acid (carbon dioxide) ; it only absorbs or quenches some of the 

 solar rays, allowing others to pass on to where the protoplasm is at 

 work, which, with the aid of these rays, alone possesses the power to 

 decompose its own food-material (carbon dioxide). 



5. As to the electric light aiding growth, it hardly applies, as plants 

 grow in darkness. The question is, whether it does enable a plant to 

 assimilate its food, ripen its wood, and otherwise perform its functions. 



Upon a careful consideration of the whole matter, I think the follow- 

 ing are fair observations to make : — 



6. So far as regards the primary question as to whether the provi- 

 sion by the Creator, of alternate light and darkness during the twenty- 

 four hours in our climate, can be dispensed with by plants, I doubt it. 

 It may be possible to interfere with it for short limited periods, as for 

 forcing or for growing short-lived plants, as Melons or Cucumbers. 



7. So far as an application of electric light during the winter months 

 to counteract night frosts to outdoor wall fruit-trees, or an appli- 

 cation of electric light in the spring to outdoor wall fruit-trees, after 

 they have been started naturally by solar light and heat into growth, 

 and continued on during darkness by electric light until the fruit is 

 ripe, I give no opinion until they are tried. 



8. So far as regards its application during the winter months by the 

 outside electric light to the cultivation of Melons and Cucumbers, 

 grown inside a house heated with hot-water apparatus as in house 

 No. 1, the results are not at present such as to warrant any favourable 

 expectation from its adoption. 



9. So far as regards its application during the winter months by 

 means of an electric lamp placed inside the house, as in house No. 2, 

 specially glazed in to prevent injury to the plants, in which case the 

 light might be said to assume the appearance, if not the characteristics, 

 of daylight, I do not give any opinion until it has been fairly tried. 



