. A history of the vegetable kingdom; embracing the physiology of plants, with their uses to man and the lower animals, and their application in the arts, manufactures, and domestic economy. Illus. by several hundred figures. Botany; Botany, Economic; 1855. 42 HISTORY OF THE VEGETABLE KINGDOM. tliouglit, to conclude tliat leaves are equivalent to the lungs of animals. Another argument in support of the doctrine was deduced from Du Hamel's experiment of besmearing the surface of the leaf with oil, in consequence of which treatment it soon died, owing, as it appeared, to the exclusion of air. Mo
. A history of the vegetable kingdom; embracing the physiology of plants, with their uses to man and the lower animals, and their application in the arts, manufactures, and domestic economy. Illus. by several hundred figures. Botany; Botany, Economic; 1855. 42 HISTORY OF THE VEGETABLE KINGDOM. tliouglit, to conclude tliat leaves are equivalent to the lungs of animals. Another argument in support of the doctrine was deduced from Du Hamel's experiment of besmearing the surface of the leaf with oil, in consequence of which treatment it soon died, owing, as it appeared, to the exclusion of air. Modern chemistry has af- forded us many other proofs of the functions of the leaves of plants. The experiments of Priestley, Ellis, Decandolle, and others, have fully estab- lished both the absorption and exhalation of gases through the medium of the leaves. From some recent experiments also it appears that vegetables, by decomposition of moisture, can supply an atmosphere to themselves; and thus, that plants will grow and thrive when in- closed in glass cases, perfectly impervious to ex- ternal changes of atmosphere, simply by decom- posing the water of the moist soil, with which they are famished.* The decomposition of the carbonic acid ab- sorbed from the air is effected in the parenchyma of the leaves, as well as in all the other green and herbaceous parts of the vegetable. When vegetables are exposed to the action of the sun, they are decomposed, the air retaining the carbon, and disengaging the oxygen. The reverse takes place when they are withdrawn from the influ- ence of light, in which case they extract from the air a portion of its oxygen, which they re- place by disengaging an equal quantity of car- bonic acid gas. It is well known that vegetables, when removed from the influence of the sun, become blanched; in other words, lose their green colour, are rendered soft and watery, and contain a larger proportion of saccharine principle. But we shall speak more particularl
Size: 1279px × 1953px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, booksubjectbo, booksubjectbotany
