THE GARDENER'S MONTHLY 



[March, 



soon as a thin colorless glass was fixed between 

 the plants and the light the pernicious influence 

 cciised — a remedy acting in wonderfully quick 

 time. Again, if the glass was fixed so as to in- 

 tercept the light only on some parts of the 

 plants, leaving others exposed to the naked rays, 

 the influence of protection and exposure showed 

 itself in one single night, and very markedly. 

 The exposed parts looked shrunk, the protected 

 parts looked sound and strong. And not the 

 leaves alone showed the marks of the destruc- 

 tive power, but also, though less markedly, the 

 young stems showed them after they had been 

 exposed to the open light at a distance of about 

 twenty feet from it. 



Now, why does that glass shade protect the 

 plants? The really illuminating rays are not 

 obstructed by it. Stokes, however, has shown, 

 in the year 1853, that the arc of electric light is 

 rich in those invisible rays of great frangibility, 

 which are of ultra violet color, and also that the 

 greater part of them is absorbed by glass. It con- 

 sequently seemed as though thesie were the ene- 

 mies of plants, whilst the illuminating rays of 

 less frangibility would stimulate their growth. To 

 arrive at greater certainty, Mr. Siemens planted 

 mustard and other quickly germinating seeds, 

 dividing the ground in equal radii, so that all 

 the plants should be at an equal distance from 

 the light. Part of them were exposed to the 

 naked light, another part was covered with a 

 pane of glass, a third with yellow glass, a fourth 

 with red, and a fifth with blue glass. The rela- 

 tive development of* the plants was noted down 

 every day, and the diti'erences were of a marked 

 character. The plants under the colorless glass 

 were strong and health}'^ beyond all the rest. 

 Next came those under yellow glass ; they were 

 as large as the former in size, but color and 

 thickness of stem were less than in the former. 

 The plants under the red glass were lanky, and 

 their leaves had a yellow tinge. Under the blue 

 glass they were still more lanky, and the leaves 

 looked sickly. The plants under the naked 

 light were worst of all, looking very poor, their 

 leaves very dark and partly shrunk. These re- 

 sults agree with those which Mr. Draper in the 

 year 1843 obtained, in his investigations of the 

 influence on plants of the different colors of the 

 solar spectrum, viz., that it is principally the 

 yellow rays which work the disintegration of 

 carbonic acid in the cells of the plants, and not 

 the violet rays, contrary to their usual chemical 

 effect. 



Mr. Siemens, after these experiments, put a 

 glass shade round the electrical lamp, and ob- 

 tained marvelous results. Peas, sown end of 

 October, gave a ripe crop on the 16th of Fafth 

 ruary. Raspberry plants, brought into the 

 greenhouse on the 16th of December, had ripe 

 fruit on the first of March ; and strawberries, 

 planted at about the same time, bore ripe fruit 

 of superior flavor on the 14th of February. 

 Grapevines making shoots on the 26th of De- 

 cember, bore ripe grapes on the 10th of March, 

 but these were more acid than usual. Wheat, 

 oats and barley grew with tremendous rapidity, 

 but did not ripen in proportion to their strength, 

 they had grown too fast, and when twelve inches 

 high had fallen to the ground. When sown out 

 of doors, and exposed until beginning of May to 

 the electrical light, hung in the open air, after 

 having been sown on the 5th of January, and 

 retarded in their growth for some time by snow 

 and frost, they developed quickly as soon as 

 mild weather set in, and had ripe grains end of 

 June following. 



The next experiment was to find whether, con- 

 trary to the doubts of botanists, such planta 

 would propagate their kind. So peas; grown 

 under the constant influence of the electiric light, 

 and gathered on the sixteenth of February, were 

 planted on the eighteenth of February. They 

 came up in a few days and grew finely. How- 

 ever further requirements will be necessary to 

 establish positive conclusions. 



Now, although darkness seems to favor length 

 of growth in stems, Mr. Siemens is of opinion, 

 after experiments made in the course of two 

 winters, that the continual stimulus of light calls 

 forth an accelerated and sound growth of the plant 

 through all its stages, from the first leaf to the 

 ripened fruit. Moreover the fruit, thus obtained, 

 is superior in size, aroma and flavor, and finally 

 the seed in it will germinate and produce. A 

 particularly strong influence had his light on a 

 Banana plant, which was twice exposed to it, first 

 during its first stage of growth, next during the 

 stage of fruiting — February and March, 1880 and 

 1881 — and produced fruit weighing about seventy- 

 five pounds, each banana of unusual size, and 

 declared by connoisseurs of unsurpassed taste. 

 Melons also succeeded remarkably and were of 

 unusual size and aroma. 



These experiments were not made to obtain 

 results in the way of quantity, but to establish 

 the influence which electric light had on plants 

 generally. Nevertheless, Mr. Siemens thinks 



