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der'd more and more fubtile, and so enabled to enter Veffels ftill finer and finer ; the thicker Part of it being at the same time secreted and deposited into the lateral Cells or Vesicles of the Bark, to defend the Plant from Cold and other external Injuries.
The Juice (or what is vulgarly call'd the Sap) of the Sap. having thus gone its Stage from the Root to the remotest Branches, and having, in every Part of its Progress, deposited something both for Alinient and for Defence, what is redundant passes out into the Bark, the Vessels whereof are inofculated with those wherein the Sap mounted; and thro’these it re-descends to the Root, and thence to the Earth again; and thus a Circulation is effected. The third and last Part of the Tbeory of Vege
The Vegetative tation, is a true Knowledge of the vegetative cubat.
Principle, Principle, or that which is the immediate Matter of the Growth or Increase of the Plant. 'Tis certain this is a Juice furnished by the Earth, and imbib'd by the absorbent Vessels in the Roots of the Plant ; this is circulated through the Substance of the Plant, and, in part, is assimilated thereto: And thus by the constant Addition of new Matter in every Circulation, the Plant is made to grow or increase its Bulk. But more particularly
This Nutritious Juice is imbibed from the Earth, and therefore must contain fome Fosil Parts, other Parts derived from Air and Rain, and others from putrified Plants and Animals, &c. and consequently in Vegetables are contained all kinds of Salts, Oil, Water, Earth, &c. if not mineral Particles too. This Juice enters the Root in forın of a fine and subtile Water.
In the Root then it is earthy, watry, acid, The State of poor, and scarce oleaginous at all. In the Trunk the Sap in its and Branches it is further prepared, tho’ it still different Stages
of Circulation, Ff2
continues acid. In the Gems or Buds it is more concocted, and, entering the Veffels of the Leaves, causes them to unfold and thew themselves. From hence it proceeds to the Leaves of the Flower, where it is still further digested: These transmit it to a greater Degree of Fineness to the Stamina ; these again to the Farina or Dust in the Apices; where, having undergone a further Maturation, it is shed into the Pistil or Style, which receives it in the manner of a Womb, where it acquires its last Perfection, fæcundates the Seed,
and gives Rife to a new Plant. The Office of
The Sap in Plants performs the same Office as the Blood in Animals, viz. to be a Vebicle to convey
the Food or Aliment to the several Parts of the Vegetable by Circulation. This Vegetable
Aliment is (according to Dr. Woodward) a certain terrestrial Matter contain’d in all Water, and is of two kinds, viz. The one properly a vegetable Matter, the other of a mineral Nature. The former of these is principally the Matter by which the Vegetable is nourished. That this is more than probable, and that the Plant owes little or nothing of its Growth to Earth or Water, is
made evident by divers Experiments. Earth and Thus Mr. Boyle raised a Plant of 3lb. and Water conduce after that another of 14 lb. was produced from a but little to the Vegetable Ali. Quantity of Earth water’d with Rain or Spring, ment, Spewn water, and which being carefully weighed dry by Experi
at first and laft, was found to have lost scarce any thing of its Weight.
AGAIN; Van Helmont dried 200lb. of Earth, and therein planted a Willow weighing 5lb. which he water'd with Rain or diftill'd Water only; and after five Years he weighed the Tree, with the Leaves it had born in the time, and found the Weight thereof to be 169 lb. 3 oz. but that the Earth had lost only 2 oz. of its Weight;
fo that the Increase of the Plant was 1313 times more than the Expence of Earth, and consequently Earth has but a small share in Vegetation.
THAT Water likewise conduces but little thereto, is evident from Dr. Woodward's Experiments. He took a Plant of common SpearMint which weighed 27 Grains, and placed it in a Vial of Water for the Space of 77 Days; in which Time it drank up 2558 Grains of Springwater, and then being taken out, weighed 42 Grains ; fo that its whole Increase was but 15 Grains, which was but 170th Part of the Water expended.
He took another Plant weighing 127 Grains, placed it in Water for 56 Days, when it weighed 255 Grains, and the Water expended was 14190 Grains, which was 110 times more than the Increase of the Plant. From these, and many other Experiments, 'tis plain that Water also has but a small share in Vegetation, and that therefore it must proceed from a peculiar vegetable Matter in Water and the Moisture of the Earth, as before observed.
SINCE then it appears that Plants imbibe such of the Perspigreat Quantities of Water or Humour, and re- ration of tain so little for Nourishment and Growth, it
Plants. follows that there must necessarily be a considerable Perspiration in Vegetables as well as in Animals, for the Discharge and Evacuation of all the fuperfluous Moisture in each Circulation. Accordingly it has been found by Experience, that a Plant of about 3lb. will perspire 30 oz. in 12 Hours Day in July, but in a warm Night not above 3 oz. and nothing in a cold Night : And also that such a Plant, if the Leaves were pluck'd off, would not perspire above 1 oz. in 12 Hours Day, which plainly shews that the Leaves are
the great Organs of Perspiration, and therefore may be calld the Lungs of the Plant. Thus much for the Vegetation of Plants, the Theory
whereof is not yet arrived to its due Perfection. Of tre second The second great Province of Botany, is to great Part of make a just and natural Distribution and ArrangeBotany.
ment of Vegetables into the several Genus's or Kinds and Classes, and to enumerate the Species and Individuals contain'd in each. To effect this,
many Persons have pursued many and different The Distribu- Methods. For since the Kinds of Plants follow tion of Plants. some general Differences or Characteristics, and
these being to be found in almost all parts of Plants ; therefore some have began to define the various kinds of Plants from their Roots, others from the Flowers, and others from the Fruit, &c. But in this Affair none has succeeded fo happily as the great Mr. Ray, whom I shall here abridge ; but shall first premise a Word or two concerning the more common and general Di
stinction of Plants and Vegetables. Indigenous First, then, with respect to Place or Cours Plants.
try, Plants are distinguish'd into (1.) Indigencus,
or such as are Natives of our own Soil or CounExotics. try ; and (2.) Exotics, such as are brought from
Foreign Countries ; as Aloes, Euphorbium, &c. Male, &c. With regard to Sex they are divided into Mal,
Female, and Hermaphrodite Plants, as before coserved. With regard to the Time of their Con
tinuance, or Period of Life, they are distinguish'd Annual. into Annual, or such as live but one Year, or
come up in the Spring and perish in the Winter ; Perennial. and Perennial, or such whose Roots endure
many Years. Again, those Plants which retain Evergreens. their Leaves in Winter are calld Evergre::5, Perdifols. and such as do not are call'd Deciduous, or Per
difols. Also Vegetables have been divided into Herbs, Skrubs, and Trees; but this is rather popular and vulgar, than just and Philosophical. Lastly, with respect to the Element they live in, Plants are divided into Terrestrial, or Land- Terrestrial. Plants ; Aquatic, or Water-Plants ; and Amphi- Aquatic. bious, or such as live indifferently in Land or Amphibious. Water.
But Mr. Ray is much more minute and nice Mr. Ray's in his celebrated Distribution of Plants into 25
Distribution Genders or Classes, which are as follow.
I. Submarine Plants, or which grow in the Sea, Submarine. on Rocks, &c. and seem to want both Flower and Seed: As Corals, Spunges, Alga, &c.
II. The Fungi, Tubera Terra, or Mushrooms, Fungous. Puff-Balls, and those Excrescences of Trees callid Jew's-Ear, Agaric, &c. all which appear to want both Flower, and Seed, and Leaves ; and have a Vegetation peculiar to themselves.
III. Mojjès of all Sorts, most of which appear Molfes. to want Flower and Seed; for which Reason these three Genus's are by Mr. Ray callid Imperfeet Plants.
IV. Capillary Plants, which are all such as Capillaries. want a Stalk, or consist of mere Leaves, and whose Seed grows like small Duft on the Backpart of the Leaves : As Maiden-hair, Spleenwort, Polypody, Fern, &c.
V. Plants which bear apetalous or stamineous Apetalous. Flowers, i. e. such as consist only of Stamina and the Perianthum, without any Leaves: As Hops, Hemp, Nettles, Docks, Sorrel, Arsesmart, Lady'sMantle, &c.
VI. Plants which have a compound Flower, La&tiferous. and which emit a sort of white Juice or Milk, when their Stalks or Branches are cut or broken off: As Lettuce, Sow-Thistle, Dandelion, Succory, Goat's-Beard, Nipplewort, &c.
VII. Plants which have a compound Flower of Discoide. a Discoide Figure, and the Seed pappose, or wing’d