Diadelphia, consists of the pea-tribe, which produce edible seeds. Syngenesia possesses the compound flowers. And the Cryptogamia contains the natural tribes of ferns, mosses, sea-weeds, and mushrooms. : Obs. The first order of the fourteenth class, denominated "Didynamia Gymnospermia" are all innocent or wholesome those of the other order are fœtid, narcotic, and dangerous: being allied to a large part of the Pentandria Monogynia, known to be poisonous, as containing henbane, night-shade, and tobacco. The whole class Tetradynamia is wholesome. Whenever the stamens are found to grow out of the calyx, they indicate the pulpy fruits of such plants to be wholesome. The papilionaceous plants are wholesome, except the seeds of the laburnum; which, if eaten unripe, are violently emetic and dangerous. Milky plants are generally to be suspected. Umbelliferous plants, which grow in dry or elevated situations, are aromatic, safe, and often wholesome; while those that inhabit low and watery places, are among the most deadly poisons. 435. Other distinctions in each class produce a division of the classes, called Orders. A further division of the orders, founded on distinctions in the flower and fruit, lead to the Genera. Other divisions of the genera, in regard to the root, trunk, leaves, &c. lead to Species: and casual differences in species are called Varieties. 436. The useful substances found in vegetables are, sugar, in the sugar-cane, beet, carrots, &c.; gum, or mucilage, which oozes from many trees; jelly, procured from many fruits; bitters, from hops and quassia: and the narcotic principle from the milk of poppies, lettuce, &c. 437. The vegetables of the greatest value to man, are those which produce gluten and starch; as wheat, potatoes, barley, beans, &c. Oils are produced by pressing the seeds or kernals of vegetables; as olives, almonds, linseed, &c. latile oils are distilled from peppermint, lavender, &c. Wax is collected from all flowers by bees. 438. Resins exude like gum from furze and other trees; and are known as balsams, varnishes, turpentine, tar, pitch, &c. Of this class, too, is Indian rubber; which exudes from certain trees in South America. Iron mixes with the substance of most vegetables; and is the cause of the beautiful colours of flowers. Pot-ash is obtained from the ashes of burnt vegetables. Obs.-The classes Monacia and Diccia, containing the pistil and stamens in different flowers, have the pistil fructified by the bees and other insects, which enter the corolla to extract the honey from the nectarium. The pollen in those flowers which have stamens only, falls on their bodies, and is carried by them to the flowers which have pistils only. And here the wisdom of the Divine Architect of nature is conspicuous, that when the pistil is shorter than the stamens, the flowers grow upright, that the pollen may fall from the anthers of the stamens on the stigma of the pistils; but when the pistil is longer than the stamen, the flower hangs downward, that the pollen in falling, may be received by the stigma of the pistil. P 439. The chemical or elementary principles of vegetables, are carbon, water, and air; or hydrogen (15,) and oxygen (85,) for the constituent parts of (100) water; and azote or nitrogen (72,) and oxygen (28,) as the constituent parts of (100) atmospheric air; and carbon. Obs. 1.-Wood burnt in a close vessel till it has neither smell nor taste, will produce the basis of all vegetable matter called charcoal; or, when purified, called carbon, which is the hardest and most indestructible substance in nature. 2. It is found, that water is nothing but a mixture of two airs or gases, one the inflammable or light gas called hydrogen, and the other the vital gas called oxygen; and water may be made by combining these; or it may also be separated into these; one hundred parts of water are combined of fifteen of hydrogen, and eighty-five of oxygen. 3.-In like manner, the air or fluid in which we live, is found to be composed of 28 parts of oxygen, or pure vital air; and 72 parts of nitrogen, or air in which animals will not live; but the due mixture of both, forms the salutary fluid or atmospheric air in which we breathe. 4.-I have explained the meaning of these easy terms in this place, in order to illustrate the beautiful provisions of vegetables which follow. There is no mystery in them; and they may be understood now as well as when I treat of Chemistry. 440. Vegetables generate, or give out oxygen or vital air, in the light or sunshine, by a natural process of their own. Air, which has been breathed by animals, is deprived of its 28 parts of oxygen, and will no longer sustain life. In like manner, a body, while burning, deprives air of its 28 parts of oxygen, and the flame will go out. An animal would die, or a flame go out, when put into air so deprived of its oxygenç, but a ve |