Page:Philosophical Transactions - Volume 003.djvu/236

 Blood in Animals, forasmuch as it continually supplies the want and expence of Sap in the exterior parts, from the slock of the sap in the Trunk, root, and branches. He understands it thus; That the Sap, necessary to the growth of the leaves, fruit, and upper branches, being dispensed and converted into the form necessary for those purposes, when the Tree is fullest of Sap, in such manner that the Sap in the innermost Coats feeds the innermost, and the sap of the outward coats the outward parts, of Fruits, &c. that which remains in the Body betwixt the several coats, and betwixt the Bark and Body, begins to condense there also, first into a Geliy, and after into Wood, Bark, Roots, &c. according to the several places to which it hath subsided. And because it condenseth faster in some parts than in others, according as they be higher or lower, (whether it be by heat or cold, or exhalation of thinner parts) the sap condensed above or below, filling less room, must needs cause the sap, which is not yet condensed, in appearance to descend or subside, and to sink as it were lower and lower in the pores of the Timber and Bark, i.e. to be less high, not descend from any place, to which it was formerly risen, unless (as in Blood-letting) when some lower part is open'd, all the sap above continually flowes thither, till the Tree be emptied, or the continual flux of the Sap (the natural Balsome of the Tree) heal the wounds, as that of the Blood does those of the Body; and so much quicker and easier, by how much the Air is more favorable, or is better kept out; which he observes for their direction, who are curious in Inoculation, as the ground of their successes or miscarriages.

The Trees observ'd by the same Dr. T. to run, are the Vine; the Birch plentifully, at body, branches, and roots; the Walnut-tree, at the roits and pruned branches; some Willows and Sallyes and some sorts of Maple; the Sycamore, which is the greater Maple (some call it the Plane) at a gash made on the bark of his body, and at the root and branches; the Poplar and Asp: The Elme and Oake are referr'd to tryal; concerning which laik some Wood-men affirm, that in such of them as are Windshaken, that have large hollownesses in their Armes and Bodies, they have found great quantity of sap in the cutting of them, whereof having drunk, they quenched their thirst without any Rh