The cause of which odd Phaenomenon, I suppose to be much the same with that of the stinging of a Nettle, for by the Microscope, I discover’d this Down to consist of a multitude of small and slender conical bodies, much resembling Needles or Bodkins, such as are represented by AB.  CD.  EF. of the first Figure of the XVI. Scheme; that their ends AAA, were very sharp, and the substance of them stiff and hard, much like the substance of several kinds of Thorns and crooks growing on Trees.  And though they appear’d very cleer and transparent, yet I could not perceive whether they were hollow or not, but to me they appear’d like solid transparent bodies, without any cavity in them; whether, though they might not be a kind of Cane, fill’d with some transparent liquor which was hardned (because the Cod which I had was very dry) I was not able to examine.

Now, being such stiff, sharp bodies, it is easie to conceive, how with rubbing they might easily be thrust into the tender parts of the skin, and there, by reason of their exceeding fineness and driness, not create any considerable trouble or pain, till by remaining in those places moistned with the humours of the body, some caustick part sticking on them, or residing within them might be dissolv’d and mix’d with the ambient juices of that place, and thereby those fibres and tender parts adjoyning become affected, and as it were corroded by it; whence, while that action lasts, the pains created are pretty sharp and pungent, though small, which is the essential property of an itching one.

That the pain also caused by the stinging of a Flea, a Gnat, a Flie, a Wasp, and the like, proceeds much from the very same cause, I elsewhere in their proper places endeavour to manifest.  The stinging also of shred Hors-hair, which in meriment is often strew’d between the sheets of a Bed, seems to proceed from the same cause.

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Observ.  XXVII. Of the Beard_ of a wilde Oat, and the use that may be made of it for exhibiting always to the Eye the temperature of the Air, as to driness and moisture._

This Beard of a wild Oat, is a body of a very curious structure, though to the naked Eye it appears very slight, and inconsiderable, it being only a small black or brown Beard or Bristle, which grows out of the side of the inner Husk that covers the Grain of a wild Oat; the whole length of it, when put in Water, so that it may extend it self to its full length, is not above an Inch and a half, and for the most part somewhat shorter, but when the Grain is ripe, and very dry, which is usualy in the Moneths of July, and August, this Beard is bent somewhat below the middle, namely, about 2/5 from the bottom of it, almost to a right Angle, and the under part of it is wreath’d lik a With; the substance of it is very brittle when dry, and it will very easily be broken from the husk on which it grows.