and from the Polonian disease one may believe them such, yet I think we have not the least encouragement to either from the Microscope, much less positively to assert them such. And perhaps the very essence of the Plica Polonica may be the hairs growing hollow, and of an unnatural constitution.
And as for the Analogie, though I am apt enough to think that the hairs of several Animals may be perforated somewhat like a Cane, or at least have a kind of pith in them, first, because they seem as 'twere a kind of Vegetable growing on an Animal, which growing, they say, remains a long while after the Animal is dead, and therefore should like other Vegetables have a pith; and secondly, because Horns and Feathers, and Porcupine's Quils, and Cats Bristles, and the long hairs of Horses, which come very neer the nature of a mans hair, seem all of them to have a kind of pith, and some of them to be porous, yet I think it not (in these cases, where we have such helps for the sense as the Microscope affords) safe concluding or building on more then we sensibly know, since we may, with examining, find that Nature does in the make of the same kind of substance, often vary her method in framing of it: Instances enough to confirm this we may find in the Horns of several creatures: as what a vast difference is there between the Horns of an Oxe, and those of some sorts of Staggs as to their shape? and even in the hairs of several creatures, we find a vast difference; as the hair of a man's head seems, as I said before, long, Cylindrical and sometime a little Prismatical, solid or impervious, and very small; the hair of an Indian Deer (a part of the middle of which is described in the third Figure of the fifth Scheme, marked with F) is bigger in compass through all the middle of it, then the Bristle of an Hogg, but the end of it is smaller then the hair of any kind of Animal (as may be seen by the Figure G) the whole belly of it, which is about two or three Inches long, looks to the eye like a thread of course Canvass, that has been newly unwreath'd, it being all wav'd or bended to and fro, much after that manner, but through the Microscope, it appears all perforated from side to side, and Spongie, like a small kind of spongy Coral, which is often found upon the English shores; but though I cut it transversly, I could not perceive that it had any pores that ran the long-way of the hair: the long hairs of Horses C C and D, seem Cylindrical and somewhat pithy; the Bristles of a Cat B, are conical and pithy: the Quils of Porcupines and Hedghoggs, being cut transversly, have a whitish pith, in the manner of a Starr, or Spur-rowel: Piggs-hair (A) is somewhat triagonal, and seems to have neither pith nor pore: And other kinds of hair have quite a differing structure and form. And therefore I think it no way agreeable to a true natural Historian, to pretend to be so sharp-sighted, as to see what a pre-conceiv'd Hypothesis tells them should be there, where another man, though perhaps as seeing, but not forestall'd, can discover no such matter.
But to proceed; I observ'd several kind of hairs that had been Dyed, and found them to be a kind of horny Cylinder, being of much about the transparency of a pretty cleer piece of Oxe horn; these appear'd quite
