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. * * * * * 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 usually in the Moneths of _July_, and _August_, this Beard is bent somewhat below the middle, namely, about ⅖ 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. If you take one of these Grains, and wet the Beard in Water, you will presently see the small bended top to turn and move round, as if it were sensible; and by degrees, if it be continued wet enough, the joint or knee will streighten it self; and if it be suffer’d to dry again, it will by degrees move round another way, and at length bend again into its former posture. If it be view’d with an ordinary single _Microscope_, it will appear like a small wreath’d Sprig, with two clefts; and if wet as before, and then look’d on with this _Microscope_, it will appear to unwreath it self, and by degrees, to streighten its knee, and the two clefts will become streight, and almost on opposite sides of the small cylindrical body. If it be continued to be look’d on a little longer with a _Microscope_, it will within a little while begin to wreath it self again, and soon after return to its former posture, bending it self again neer the middle, into a kind of knee or angle.