to ascend through the Body of the _Pith_? The plain reason is, because they are all fill’d with Ayr. Whereas the _Pith_ in a Vegetating Plant, as its Parts or Pores are still generated, they are at the same time also fill’d with _Sap_; which, as ’tis gradually spent, is still repair’d by more succeeding, and so the Ayr still kept out; as in all primitive growths, and the _Pith_ of _Elder_ it self: Yet the same _Pith_, by reason of the following Winter, wanting a more copious and quick supply of _Sap_, thus once become, ever after keeps dry. And since in the aforesaid Trial the Liquor only ascends by the sides of the _Pith_, that is of its broken Pores, we should thence by the same reason conclude that they are not penetrable by the breadth neither, and so no way; and then it need not be ask’d what would follow. But certainly the _Sap_ in the Pores of the _Pith_ is discharged and repaired every moment, as by its shriv’ling up; upon cutting the Plant is evident. We suppose then, that as the _Sap_ ascendeth into the _Trunk_ by the _Lignous Body_, so partly also by the _Pith_. For a piece of _Cotton_ with one end immers’d in some tinged Liquor, and with the other erect above, though it will not imbibe the Liquor so far as to over-run at the top, yet so as to advance towards it, it will; so here, the _Pith_ being a porous and spongy Body, and in its Vegetating state its Pores also permeable, as a curious Filtre of Natures own contrivance, it thus advanceth, or as people use to say, sucks up the _Sap_. Yet as it is seen of the Liquor in the Cotton; so likewise are we to suppose it of the _Sap_ in the _Pith_; that though it riseth up for some way, yet is their some term, beyond which it riseth not, and towards which the motion of the ascending _Sap_ is more and more broken, weak and slow, and so the quantity thereof less and less. But because the _Sap_ moveth not only by the length, but breadth of the _Pith_; at the same time therefore as it partly ascendeth by the _Pith_, it is likewise in part pressed into the _Lignous Body_ or into its Pores. And since the motion of the _Sap_ by the breadth of the _Pith_ not being far continued, and but collateral, is more prone and easie than the perpendicular, or by its length; it therefore follows, that the collateral motion of the _Sap_, at such a height or part of the _Pith_, will be equally strong with the perpendicular at another part, though somewhat beneath it; and that where the perpendicular is more broken and weak, the collateral will be less; and consequently where the perpendicular tendency of the _Sap_ hath its term, the collateral tendency thereof, and so its pressure into the Pores of the _Lignous Body_ will still continue. Through which, in that they are small, and so their sides almost contiguous, the _Sap_ as fast as pressed into them will easily run up; as betwixt the two halves of a Stick first slit, and then tied somewhat loosely together, may also any Liquor be observed to do.