454. Resins exude like gum from firs and other trees; and are known as balsams, varnishes, turpentine, tar, pitch, &c. Of this class, too, is Indian rubber; which is a gum that exudes from a certain tree in South America.

Iron also mixes with the substance of most vegetables; and is the cause of the beautiful colours of flowers. Potash is obtained from the ashes of burnt vegetables; as kelp, vine, fern, &c.

Obs.-The classes monocia and dioecia, which have the pistil and stamens in different flowers, and on different plants, 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 it deserves to be noticed, as a proof of the contrivance of the DIVINE ARCHITECT of Nature, that when the pistil is shorter than the stamens, the flowers grow upright, that the pollen may fall from the anthers of the stamens or the stigma of the pistils; but when the pistil is longer than the stamen, the flower bangs downward, that the pollen, in falling, may be caught by the stigma of the pistil. Who can paint

Like Nature? Can imagination boast,
Amidst his gay creation, hues like bers?
And can he mix them with that matchless skill,
And lay them on so delicately fine,

And lose them in each other as appears
In every bud that blows? If fancy, then,
Unequal fails beneath the pleasing task,
Ah! What shall language do?

THOMSON.

455. 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 most indestructible substance in nature. The diamond approaches the nearest to pure carbon of any substance at present known.

2. It is found that water is nothing but a composition of twe airs or gasses, 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, may also be separated into these; one hundred parts water are composed 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 azotic gas; but the due mixture of both, forms a 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.

456. 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 give out 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.

457. 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.

458. 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.

459. 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 swells
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.

460. 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 fold together 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 na ture 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.