The Tetradynamia contains the natural tribe of flowers, which are antiscorbutic.

The Monadelphia is composed chiefly of the mallow tribe,

Diadelphia consists of the pea-tribe, which produce edible seeds.

Syngenesia possess the compound flowers.

And the cryptogamia contain the natural tribes of ferns, mosses, sea-weeds, and mush

rooms.

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.

442. Other distinctions in each class produce a division of the classes, called Orders. A further division of the orders, founded on distinctions in the nectarium, 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.

443. The natural substances found in all vegetables are, sugar in the sugar-cane, beet, carrots, &c.; gum, or mucilage, which oozes from many trees; jelly, procured from many fruits; tar,

446. 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 pure earth, and 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 vita! 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.

447. 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 oxygen; but a

vegetable will then thrive in it, and will restore it to its original power of sustaining animal life.

Obs.---Hence, the oxygen of the whole atmosphere would, in due time, be consumed by the breathing of animals and by flame, but for this provision of nature. The leaves of vegetables create oxygen in the day-time, and keep up the due proportion which is necessary to the support of animal life: the leaves of aquatic and herbaceous plants produce it, however, in the greatest quantity.

448. The saccharine and oily productions of vegetables are parts of their sap or juices; but the turpentine, the bitter, and the acid principles, are considered as the effect of preparation

or secretion.

The green colour of vegetables arises from the oil they contain; the rays of the sun extracting the oxygen from the outer surface, and leaving the carbon and hydrogen, which are known to be the constituent parts of oil.

449. Healthy vegetables perspire water by the under part of their leaves, equal to one-third of their weight every twenty-four hours; by which part they also give out oxygen.

450. Nor do they derive their substance in a principal degree from the matter of the soil in which they grow; but they are created by a vital principle of their own, out of air and water, and of the imperceptible matters combined with air and water, from which all their distinctions of smell, taste, and substance, are derived!

Hail, Source of Being! Universal Soul

Of heaven and earth! Essential Presence, hail !
By THEE, the various vegetative tribes,
Wrapt in a filmy net, and clad with leaves,
Draw the live ether, and imbibe the dew:
By THEE, disposed into congenial soils,

Stands each attractive plant, and sucks and swelle
The juicy tide, a twining mass of tubes:
At THY Command, the vernal sun awakes
The torpid sap, detruded to the root

By wintry winds; that now in fluent dance,
And lively fermentation, mounting, spreads

All this innumerous-colour'd scene of things. THOMSON. 451. Some plants exhibit signs of great sensibility, besides, the effects in nearly all arising from the presence or absence of the rays of the sun these are the sensitive plant, whose leaves drop on being touched by the hand; and Venus's mouse-trap, which closes on any insect that goes into it, and stings it to death.

Obs.---Throughout universal nature, a gradation of beings may be traced; and yet their particular differences elude the observation, like the various colours of the rainbow, blending and mixing with each other. Where vegetation ceases, or seems to cease, perception begins; and we trace some of the first rudiments, or sparks of it, in the actinia, or sea-anemone, the oyster, and the snail. The polypus ranks as the first of plants, and the last of animals; if its propagation, as some naturalists affirm, can be effected by cuttings, similar to the multiplication of plants by slips and suckers. Then, it ascends through various gradations of beings, distinguished by more enlarged and active faculties, more perfect and more numerous organs, to those creatures which approach to the nature of man. We behold the distant resemblance of his sagacity in the elephant; of his social attachments in the bee and the beaver; and the rude traces of his form in the ourang-outang.

XX. Of Animated Nature.

452. Animals are a class of beings differently organized from vegetables; because they have different destinations, have different habits, and