452 



GARDENING AS A SCIENCE. 



But if the beams of light be absorbed, 

 they must of necessity be masked or con- 

 cealed, till excited by some powerful agent 

 which disturbs the natural equilibrium; and 

 such disturbance is happening every day 

 and hour, in every act of abrasion, percus- 

 sion, motion, chemical action, and so forth. 



The source of light is the sun, whence 

 its difTusion is universal. That mighty 

 orb, being the fountain of pure ethereal 

 light, electrises all bodies, (primary or se- 

 condary,) and produces a condition in such 

 bodies which causes them to attract each 

 other, and to be attracted themselves, uni- 

 versally and interchangeably. 



We may not be able to withdraw the veil 

 of mystery; but the experiments of Profes- 

 sor Faraday are quite conclusive of the 

 fact, that a stupendous quantity of electri- 

 city combines with the elements of matter, 

 and gives them form and consistence; it 

 retains them in their natural condition and 

 order. This electricity is derived from the 

 sun; and, as all light comes from that 

 source, it becomes the^rs^ grand connective 

 principle. 



Light, we have said, pervades, imbues, 

 influences all things. True, we do not per- 

 ceive it in a drop of water ; yet water con- 

 tains the elements of tremendous combus- 

 tion. Flint does not manifest light, neither 

 does steel ; yet who doubts their excitabi- 

 lity by percussion.? Hydrogen gas, the 

 lightest of all known airs, is invisible ; yet 

 let a stream of it be forced through a fine 

 aperture upon a bit of spongy platinum, the 

 cold metal will become heated and ignite 

 the gas. A piece of glass, and a small 

 square of black silk, are both inert and cold 

 bodies ; yet rub them together, they exhibit 

 sparks of ethereal light. A little white su- 

 gar, mixed with powdered chlorate of po- 

 tass, will burst into flame on applying a 

 drop of sulphuric acid. On the same prin- 



ciple, our lucifer matches act as excitable 

 media of masked electrical light. 



As the principle of solar electric light be- 

 comes better understood, the theory of la- 

 tent heat will be forgotten. Philosophers 

 are advancing on the road ; but, like the 

 world, they cling to old prejudices. For 

 what Davy and.Faraday have effected and 

 improved, we may be thankful ; but we are 

 far from the simplicity of science. 



Light, as applied to plants endowed with 

 vitality, is an active principle ; they drink 

 it in, and colour is imparted to their foliage 

 and flowers ; but it is a mistake to imagine 

 that the direct ray is always essential ; for 

 diffused light acts perfectly well on many 

 vegetables; and even in a dark cellar, a 

 rhubarb plant exhibits gorgeous tints of red 

 and yellow. The air itself is replete with 

 lights, and this medium cannot be excluded. 



Inert vegetable matters, void of life, as 

 straw, haulm, dry wood, are vehicles of 

 this mighty principle, which require only a 

 spark, or even friction duly applied, to raise 

 it into activity. They there burst into rapid 

 combustion, and produce substances, the 

 existence of which could be no more sus- 

 pected by the ignorant, than was the light 

 which blazed from a dark mass of lamp- 

 black, excited to spontaneous combustion 

 (as it is improperly termed,) by electro- 

 chemical agency. 



Light, it appears, is to vegetables the 

 stimulus of the vital principle ; its operation 

 during the day effects the elaboration of 

 the elements of water and carbon, producing 

 the specific essences of the individual spe- 

 cies. It is the chief agent of maturation, 

 as well as of colour; its absence during 

 night, and in winter, produces torpor ; and 

 repose is as essential to plants as to animals. 

 Plants, made the subject of experiment, are 

 always placed in artificial situations ; there- 

 fore, we cannot trace the direct agency of 



