ong-ways.

This Figure plainly enough shews in what manner those clefts, K and L
divided the wreath'd Cylinder into two unequal parts, and also of what kind
of substance the whole body consists; for by cutting the same Beard in many
places, with transverse Sections, I found much the same appearance with
this express'd; so that those pores seem to run, as in most other such Cany
bodies, the whole length of it.

The clefts of this body KK, and LL, seem'd (as is also express'd in the
Figure) to wind very oddly in the inner part of the wreath, and in some
parts of them, they seem'd stuffed, as it were, with that Spongie
substance, which I just now described.

This so oddly constituted Vegetable substance, is first (that I have met
with) taken notice of by _Baptista Porta_, in his _Natural Magick_, as a
thing known to children and Juglers, and it has been call'd by some of
those last named persons, the better to cover their cheat, the Legg of an
_Arabian Spider_, or the Legg of an inchanted _Egyptian fly_, and has been
used by them to make a small Index, Cross, or the like, to move round upon
the wetting of it with a drop of Water, and muttering certain words.

But the use that has been made of it, for the discovery of the various
constitutions of the Air, as to driness and moistness, is incomparably
beyond any other, for this it does to admiration: The manner of contriving
it so, as to perform this great effect, is onely thus:

Provide a good large Box of Ivory, about four Inches over, and of what
depth you shall judge convenient (according to your intention of making use
of one, two, three, or more of these small Beards, ordered in the manner
which I shall by and by describe) let all the sides of this Box be turned
of Basket-work (which here in _London_ is easily enough procur'd) full of
holes, in the manner almost of a Lettice, the bigger, or more the holes
are, the better, that so the Air may have the more free passage to the
inclosed Beard, and may the more easily pass through the Instrument; it
will be better yet, though not altogether so handsom, if insteed of the
Basket-work on the sides of the Box, the bottom and top of the Box be
join'd together onely with three or four small Pillars, after the manner
represented in the 4. Figure of the 15. _Scheme_. Or, if you intend to make
use of many of these small Beards join'd together, you may have a small
long Case of Ivory, whose sides are turn'd of Basket-work, full of