OCR Text |
Show 134 VEGETABLE COLOURS. at the red end. The property which begins at the blue end hinders oxidation, and in some cases re• stores oxidized bodies to their former state. When vegetables are in a state of vigorous and healthy action, they absorb or drink up the red rays of the sun's light, and return the green to the eye; and the red light, or that invisible oxidizing agency which accompanies the red end of the spectrum, facilitates the combination of the oxygen of the atmosphere with the surplus carbon of the plants, and also forms the acid juice of unripe fruits ; while when they decay, and the oxidation ceases, they give out the yellow or the red rays, or the russety and brown tints, which are various mixtures of red, yellow, and green. Fruits too, which are almost all green in their growing states, receive the yellows and reds, and sometimes pass into black, or absorb the entire light, get very sweet and mellow, and soon decay. Coe's golden drop, or any of the plums which ripen to a golden orange, spotted with red, are so far instances of the progress of this action of light upon fruits-or of fruits upon light. While green they are very austere ; but as the green fades into yellow, the austerity diminishes; and when they begin ~o be spotted with red, they have little or no austenty. These changes are not, however, universal, or even general ; for many of the sweetest fruits that we have are green when they are ripe, and red vegetables are often the sourest of their class : so that, thol;lgh the light may be the agent in these cases, its action is modified by the nature of the plant; and it may return the red rays from being already saturated with, and as well as from ceasing to elaborate, acid juice. The philosophy of light is, however, a very obscure and imperfect philosophy; and there are not many parts of knowledge in which theories are more likely to lead us wrong. The observation of it has the advantage of being, perhaps, the most pleasing OBSERVATION OF LIGJIT. 13:; and ce~tainly the f}asiest Qf all observation : and thus, w1th ~knowledge of some of the best krwwn and mos.t obv~ous principles, any inan who choqses may der1ve his full mpasure of enjQyment from it. 91oud or no cloud, the light on the scene changes 1ts appearance every hour; and there is a gradual change througho~t. the seasons. In the spring, the red and t~e oxydiZifl:g hea~, a~ welJ as the fqqing of the blue mto the vwlet tints, ~nd tpe deoxydizing epergr of .th~t end of the spectr~m, are busily at work m brmgmg forward ~ll the yqung leaves of the year ; so that the yel_low and tht:1 plue are sent back to refresh the eye wJth tpe lovely green-the indicator of the greatest action iq. the nJajority of vegetables. Thus, when the plants of the season and the a.nnual shoots of th~ tr~es have attained . their full SIZe, and the seeqs of the future successions are abou~ to be pr.epared, the o~ydi71ing action becomes les~ m. the delJCate texture of the flower.$ · and most of their petals absorb chiefly either the' y,ellow or the blue, so that they seldorq give back the green. The colours appr?ximate to the golden yellow, the orange, and the mtense red, in proportion to the warmth of the climate aqd the year, and also to the advanced heat of the s~a$on. Few early plants h~ve ~ed fJ.owers, though soll}e of them are tiqted With pmk. In cqld places, al~o, there are not- many of the flowers r.ed, while the littl~ oq~s on the stony and warm moors, even at considerable elevations are of that . co~our: Tropical vegetatiqn1 on tn~ other hand, IS rJCh m spar.let ~d gold, and the tints of the flowers of early autumn are the richest in the. whole season. .A.t;ttumn is ;rich in hpes for a whtle ; but they are, h~e the hectic flu~fl on the cheeks of the consumptive, tl:Ie signs of djssolution, ~n4 when they haye pas~ed the dingy hue of winter IS put on. In the northern regiQns, the snow serves as ~ mantle to cover the earth, and suspends all actiOn between its surface and the sun, while the. |