How crops growA treatise on the chemical composition, structure, and life of the plant, for all students of agriculture .. . ff to the surface. Silica, as we have seen, is oftenfound in the cuticle, but it is usually imbedded in the cell-wall. In certain plants, other substances accumulate inconsiderable quantity without the cuticle. A striking ex-ample is furnished by Saxifraga crustata, a low Europeanplant, which is found in lime leaves of this saxifrage areentirely coated with a scaly in-crustation of carbonate of limeand carbonate of magnesia. Atthe edges of the leaf, this incrus
How crops growA treatise on the chemical composition, structure, and life of the plant, for all students of agriculture .. . ff to the surface. Silica, as we have seen, is oftenfound in the cuticle, but it is usually imbedded in the cell-wall. In certain plants, other substances accumulate inconsiderable quantity without the cuticle. A striking ex-ample is furnished by Saxifraga crustata, a low Europeanplant, which is found in lime leaves of this saxifrage areentirely coated with a scaly in-crustation of carbonate of limeand carbonate of magnesia. Atthe edges of the leaf, this incrusta-tion acquires a considerable thick-ness, as is illustrated by figure 26,a. In an analysis made by linger,to whom these facts are due, thefresh, (undried,) leaves yielded toa dilute acid ° |„ of carbonateof liine, and ° |„ of carbonateof magnesia. linger learned by microscopicinvestigation that this excretion of carbonates proceedsmostly from a series of glandular expansions at the marginof the leaf, which are directly connected with the sap-ductsof the plant. {8itzherichte der Wien. Akad., 43, p. 519.). ??|) d<^ AFig. 26. THE ASH OB PLANTS. 193 In figure 26, a represents the appearance of a leaf, magnified 4X diam-eters. Around the borders are seen the scales of catbonate of lime;some of these have been detached, leaving round pits on the surface ofthe leaf: c, d, exhibit the scales themselves, e in profile: 6 shows a leaf,freed from its incrustation by an acid, aud from its cuticle by potash-solution, so as to exhibit the veins, (ducts,) and glands, whose coursethe carbonate of lime chiefly takes in its passage through the plant. Further as to the state of ash-ingredients.—^It is by no means true that the ash-ingredients always exist in plantsin the forms under -which they are otherwise familiarto us. Arendt and Hellrlegel have studied the proportions ofsoluble and insoluble matters, the former in the ripe oatplant, and the latter in clover at various sta
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectagricul, bookyear1868
