Page:Philosophical Transactions - Volume 004.djvu/76

 and in the prick't Circles between the severall coats of Wood; but also through the very Body of the Wood. For, several young Birches being nimbly cut off at one blow with a sharpe axe, and white paper immediately held hard upon the topp of the remaining trunk, we stuck downe pins in all the points of the paper as they appear'd wet: and at last, when the most of the paper became wet, taking it away, but leaving the pins sticking, we found them without any order, some in the Circles, and some in the Wood between. And yo confirm this further, we caused the Body of a Tree to be cut off aslope, and then cut the opposite side aslope likewise, till we brought the top to a narrow edge; ordering the matter so, that the whole edge consisted of part of a coat of Wood, and had nothing of a prick't Circle in it, which notwithstanding, the Sap ascended to the very top of this edge, and wetted a paper laid upon it.

8. To find out the motion of the Sap, whether it ascended only, or descended also; we bored a hole in a large Birch, out of which a drop fell every 4th or 5th pulse. Then, about a hands breadth just under the hole, we saw'd into the Body of the tree, deeper than the hole: whereupon the bleeding diminish'd about one half, and having. saw'd Iust above this hole to the same depth, the bleeding from the Hole ceas'd quite; and from the saw'd furrow below decreas'd about half: and it continued bleeding a great while after at both the saw'd furrows, the hole in the middle remaining dry. We repeated this with much the like success upon a Sycamore.

9. Some Trees of the same kind and age bleed at great deal faster and sooner than others; but always Old trees sooner and faster than Young.

10. A wound, made before the Sap rises, will bleed when it doth rise.

11. While we were making these Experiments, the weather changed from warme to very cold; whereupon the bleeding in the Birches, which begun to abate before, ceas'd quite. But all the Sycamore and Walnut-trees, we had wounded, bled abundantly; (some whereof before bled not at all, and those that did, did so but slowly;) and so continued Rh