256 THE SCIENTIPIC PAPERS OF 



These results are confirmatory of those obtained by Dr. J. W. 

 Draper (see ' Scientific Memoirs,' by J. "W. Draper, M.D., LL.D. r 

 Memoir X.) in his valuable researches on plant cultivation in the 

 solar spectrum in 1843, which led him to the conclusion, in 

 opposition to the then prevailing opinion, that the yellow ray, and 

 not the violet ray, was most efficacious in promoting the decompo- 

 sition of carbonic acid in the vegetable cell. 



Having in consequence of these preliminary inquiries determined 

 to surround the electric arc with a clear glass lantern, more satis- 

 factory results were soon observable. Thus peas which had been 

 sown at the end of October produced a harvest of ripe fruit on the 

 16th of February, under the influence, with the exception of 

 Sunday nights, of continuous light. Raspberry stalks put into 

 the house on the 16th of December produced ripe fruit on the 1st 

 of March, and strawberry plants planted about the same time 

 produced ripe fruit of excellent flavour and colour on the 14th of 

 February. Vines which broke on the 2(!th of December produced 

 ripe grapes of stronger flavour than usual on the 10th of March. 

 Wheat, barley, and oats shot up with extraordinary rapidity under 

 the influence of continuous light, but did not arrive at maturity ; 

 their growth having been too rapid for their strength, caused 

 them to fall to the ground after having attained the height of 

 about 12 inches. 



Seeds of wheat, barley, and oats planted in the open air and 

 grown under the influence of the external electric light produced,, 

 however, more satisfactory results ; having been sown in rows on 

 the 6th of January, they germinated with difficulty on account of 

 frost and snow on the ground, but developed rapidly when milder 

 weather set in, and showed ripe grain by the end of June, having; 

 been aided in their growth by the electric light until the beginning 

 of May. Doubts have been expressed by some botanists whether 

 plants grown and brought to maturity under the influence of 

 continuous light would produce fruit capable of reproduction ; 

 and in order to test this question, the peas gathered on the 16th 

 of February from the plants which have been grown under almost 

 continuous light action were replanted on the 18th of February. 

 They vegetated in a few days, showing every appearance of 

 healthy growth. Further evidence on the same question will be 

 obtained by Dr. Gilbert, F.R.S., who has undertaken to experi- 





