Micrographia Part 14

But that they are Animal Substances, the _Chymical_ examination of them seems to manifest, they affording a volatil Salt and spirit, like _Harts-Horn_, as does also their great strength and toughness, and their smell when burn'd in the Fire or a Candle, which has a kind of fleshy sent, not much unlike to hair. And having since examin'd several Authors concerning them, among others; I find this account given by _Bellonius_, in the XI. _Chap._ of his 2d Book, _De Aquatilibus_. _Spongiae recentes_, says he, _a siccis longe diversae, scopulis aquae marinae ad duos vel tres cubitos, nonnunquam quatuor tantum digitos immersis, ut fungi arboribus adhaerent, sordido quodam succo aut mucosa potius sanie refertae, usque ade foetida, ut vel eminus nauseam excitet, continetur autem iis cavernis, quas inanes in siccis & lotis Spongiis cernimus: Putris pulmonis modo nigrae conspiciuntur, verum quae in sublimi aquae nasc.u.n.tur multo magis opaca nigredine suffusae sunt. Vivere quidem Spongias adhaerendo _Aristoteles_ censet: absolute vero minime: sensumque aliquem habere, vel eo argumento (inquit) credantur, quod difficillime abstrahantur, nisi clanculum agatur: Atq; ad avulsoris accessum ita contrahantur, ut eas evellere difficile sit, quod idem etiam faciunt quoties flatus tempestatesque urgent. Puto autem illis succ.u.m sordidum quem supra diximus carnis loco a natura attributum fuisse: atque meatibus latioribus tanquam intestinis aut interaneis uti.

Caeterum pars ea quae Spongiae cautibus adhaerent est tanquam folii petiolus, a quo veluti collum quoddam gracile incipit: quod deinde in lat.i.tudinem diffusum capitis glob.u.m facit. Recentibus nihil est fistulosum, haesitantque tanquam radicibus. Superne omnes propemodum meatus concreti latent: inferne ver quaterni aut quini patent, per quos eas sugere existimamus_. From which Description, they seem to be a kind of Plant-Animal that adheres to a Rock, and these small _fibres_ or threads which we have described, seem to have been the Vessels which ('tis very probable) were very much bigger whil'st the _Interst.i.tia_ were fill'd (as he affirms) with a mucous, pulpy or fleshy substance; but upon the drying were shrunk into the bigness they now appear.

The texture of it is such, that I have not yet met with any other body in the world that has the like, but onely one of a larger sort of Sponge (which is preserv'd in the _Museum Harveanum_ belonging to the most Ill.u.s.trious and most learned Society of the _Physicians_ of _London_) which is of a horney, or rather of a _petrify'd_ substance. And of this indeed, the texture and make is exactly the same with common Sponges, but onely that both the holes and the _fibres_, or texture of it is exceedingly much bigger, for some of the holes were above an Inch and half over, and the _fibres_ and _texture_ of it was bigg enough to be distinguished easily with ones eye, but conspicuously with an ordinary single _Microscope_. And these indeed, seem'd to have been the habitation of some Animal; and examining _Aristotle_, I find a very consonant account hereunto, namely, that he had known a certain little Animal, call'd _Pinnothera_, like a Spider, to be bred in those caverns of a Sponge, from within which, by opening and closing those holes, he insnares and catches the little Fishes; and in another place he says, That 'tis very confidently reported, that there are certain Moths or Worms that reside in the cavities of a Sponge, and are there nourished: Notwithstanding all which Histories, I think it well worth the enquiring into the History and nature of a Sponge, it seeming to promise some information of the Vessels in Animal substances, which (by reason of the solidity of the interserted flesh that is not easily remov'd, without destroying also those interspers'd Vessels) are hitherto undiscover'd; whereas here in a Sponge, the _Parenchyma_, it seems, is but a kind of mucous gelly, which is very easily and cleerly wash'd away.

The reason that makes me imagine, that there may probably be some such texture in Animal substances, is, that examining the texture of the filaments of tann'd Leather, I find it to be much of the same nature and strength of a Sponge; and with my _Microscope_, I have observ'd many such joints and k.n.o.bs, as I have described in Sponges, the _fibres_ also in the hollow of several sorts of Bones, after the Marrow has been remov'd, I have found somewhat to resemble this texture, though, I confess, I never yet found any texture exactly the same, nor any for curiosity comparable to it.

The filaments of it are much smaller then those of Silk, and through the _Microscope_ appear very neer as transparent, nay, some parts of them I have observ'd much more.

Having examin'd also several kinds of Mushroms, I finde their texture to be somewhat of this kind, that is, to consist of an infinite company of small filaments, every way contex'd and woven together, so as to make a kind of cloth, and more particularly, examining a piece of Touch-wood (which is a kind _Jews-ear_, or Mushrom, growing here in _England_ also, on several sorts of Trees, such as Elders, Maples, Willows, &c. and is commonly call'd by the name of _s.p.u.n.k_; but that we meet with to be sold in Shops, is brought from beyond Seas) I found it to be made of an exceeding delicate texture: For the substance of it feels, and looks to the naked eye, and may be stretch'd any way, exactly like a very fine piece of _Chamois_ Leather, or wash'd Leather, but it is of somewhat a browner hew, and nothing neer so strong; but examining it with my _Microscope_, I found it of somewhat another make then any kind of Leather; for whereas both _Chamois_, and all other kinds of Leather I have yet view'd, consist of an infinite company of filaments, somewhat like bushes interwoven one within another, that is, of bigger parts or stems, as it were, and smaller branchings that grow out of them; or like a heap of Ropes ends, where each of the larger Ropes by degrees seem to split or untwist, into many smaller Cords, and each of those Cords into smaller Lines, and those Lines into Threads, &c. and these strangely intangled, or interwoven one within another: The texture of this Touch-wood seems more like that of a Lock or a Fleece of Wool, for it consists of an infinite number of small filaments, all of them, as farr as I could perceive, of the same bigness like those of a Sponge, but that the _filaments_ of this were not a twentieth part of the bigness of those of a Sponge; and I could not so plainly perceive their joints, or their manner of interweaving, though, as farr as I was able to discern with that _Microscope_ I had, I suppose it to have some kind of resemblance, but the joints are nothing neer so thick, nor without much trouble visible.

The filaments I could plainly enough perceive to be even, round, cylindrical, transparent bodies, and to cross each other every way, that is, there were not more seem'd to lie _horizontally_ then _perpendicularly_ and thwartway, so that it is somewhat difficult to conceive how they should grow in that manner. By tearing off a small piece of it, and looking on the ragged edge, I could among several of those _fibres_ perceive small joints, that is, one of those hairs split into two, each of the same bigness with the other out of which they seem'd to grow, but having not lately had an opportunity of examining their manner of growth, I cannot positively affirm any thing of them.

But to proceed, The swelling of Sponges upon wetting, and the rising of the Water in it above the surface of the Water that it touches, are both from the same cause, of which an account is already given in the sixth Observation.

The substance of them indeed, has so many excellent properties, scarce to be met with in any other body in the world, that I have often wondered that so little use is made of it, and those onely vile and sordid; certainly, if it were well consider'd, it would afford much greater conveniencies.

That use which the Divers are said to make of it, seems, if true, very strange, but having made trial of it my self, by dipping a small piece of it in very good Sallet-oyl, and putting it in my mouth, and then keeping my mouth and nose under water, I could not find any such thing; for I was as soon out of breath as if I had had no Sponge, nor could I fetch my breath without taking in water at my mouth; but I am very apt to think, that were there a contrivance whereby the expir'd air might be forc'd to pa.s.s through a wet or oyly Sponge before it were again inspir'd, it might much cleanse, and strain away from the Air divers fuliginous and other noisome steams, and the dipping of it in certain liquors might, perhaps, so renew that property in the Air which it loses in the Lungs, by being breath'd, that one square foot of Air might last a man for respiration much longer, perhaps, then ten will now serve him of common Air.

Observ. XXIII. _Of the curious texture of _Sea-weeds_._

For curiosity and beauty, I have not among all the Plants or Vegetables I have yet observ'd, seen any one comparable to this Sea-weed I have here describ'd, of which I am able to say very little more then what is represented by the second _Figure_ of the ninth _Scheme_: Namely, that it is a Plant which grows upon the Rocks under the water, and increases and spreads it self into a great tuft, which is not onely handsomely branch'd into several leaves, but the whole surface of the Plant is cover'd over with a most curious kind of carv'd work, which consists of a texture much resembling a Honey-comb; for the whole surface on both sides is cover'd over with a mult.i.tude of very small holes, being no bigger then so many holes made with the point of a small Pinn, and rang'd in the neatest and most delicate order imaginable, they being plac'd in the manner of a _Quincunx_, or very much like the rows of the eyes of a Fly, the rows or orders being very regular, which way soever they are observ'd: what the texture was, as it appear'd through a pretty bigg Magnifying _Microscope_, I have here adjoin'd in the first _Figure_ of the 14. _Scheme._ which round Area ABCD represents a part of the surface about one eighth part of an Inch in Diameter: Those little holes, which to the eye look'd round, like so many little spots, here appear'd very regularly shap'd holes, representing almost the shape of the sole of a round toed shoe, the hinder part of which, is, as it were, trod on or cover'd by the toe of that next below it; these holes seem'd wall'd about with a very thin and transparent substance, looking of a pale straw-colour; from the edge of which, against the middle of each hole, were sprouted out four small transparent straw-colour'd Thorns, which seem'd to protect and cover those cavities, from either side two; neer the root of this Plant, were sprouted out several small branches of a kind of b.a.s.t.a.r.d _Coralline_, curiously branch'd, though small.

And to confirm this, having lately the opportunity of viewing the large Plant (if I may so call it) of a Sponge _petrify'd>_, of which I made mention in the last Observation, I found, that each of the Branches or Figures of it, did, by the range of its pores, exhibit just such a texture, the rows of pores crossing one another, much after the manner as the rows of eyes do which are describ'd in the 26. _Scheme_: _Coralline_ also, and several sorts of white _Coral_, I have with a _Microscope_ observ'd very curiously shap'd. And I doubt not, but that he that shall observe these several kinds of Plants that grow upon Rocks, which the Sea sometimes overflows, and those heaps of others which are vomited out of it upon the sh.o.r.e, may find mult.i.tudes of little Plants, and other bodies, which like this will afford very beautifull objects for the _Microscope_; and this _Specimen_ here is adjoin'd onely to excite their curiosities who have opportunity of observing to examine and collect what they find worthy their notice; for the Sea, among terrestrial bodies, is also a _prolifick_ mother, and affords as many Instances of _spontaneous_ generations as either the Air or Earth.

Observ. XXIV. _Of the surfaces of _Rosemary_, and other leaves._

This which is delineated within the circle of the second _Figure_ of the 14. _Scheme_, is a small part of the back or under side of a leaf of Rosemary, which I did not therefore make choice of because it had any thing peculiar which was not observable with a _Microscope_ in several other Plants, but because it exhibits at one view,

First, a smooth and shining surface, namely, AB, which is a part of the upper side of the leaf, that by a kind of hem or doubling of the leaf appears on this side. There are mult.i.tudes of leaves, which surfaces are like this smooth, and as it were quilted, which look like a curious quilted bagg of green Silk, or like a Bladder, or some such pliable transparent substance, full stuffed out with a green juice or liquor; the surface of Rue, or Herbgra.s.s, is polish'd, and all over indented, or pitted, like the Silk-worm's Egg, which I shall anon describe; the smooth surfaces of other Plants are otherwise quilted, Nature in this, as it were, expressing her Needle-work, or imbroidery.

Next a downy or bushy surface, such as is all the under side almost, appearing through the _Microscope_ much like a thicket of bushes, and with this kind of Down or Hair the leaves and stalks of mult.i.tudes of Vegetables are covered; and there seems to be as great a variety in the shape, bulk, and manner of the growing of these secundary Plants, as I may call them (they being, as it were, a Plant growing out of a Plant, or somewhat like the hairs of Animals) as there is to be found amongst small shrubs that compose bushes; but for the most part, they consist of small transparent parts, some of which grow in the shape of small Needles or Bodkins, as on the Thistle, Cowag-ecod and Nettle; others in the form of Cat's claws, as in Cliders, the beards of Barley, the edges of several sorts of Gra.s.s and Reeds, &c. in other, as Coltsfoot, Rose-campion, Aps, Poplar, Willow, and almost all other downy Plants, they grow in the form of bushes very much diversify'd in each particular Plant, That which I have before in the 19.

Observation noted on Rose-leaves, is of a quite differing kind, and seems indeed a real Vegetable, distinct from the leaf.

Thirdly, among these small bushes are observable an infinite company of small round b.a.l.l.s, exactly Globular, and very much resembling Pearls, namely, CCCC, of these there maybe mult.i.tudes observ'd in Sage, and several other Plants, which I suppose was the reason why _Athanasius Kircher_ supposed them to be all cover'd with Spiders Eggs, or young Spiders, which indeed is nothing else but some kind of gummous exsudation, which is always much of the same bigness. At first sight of these, I confess, I imagin'd that they might have been some kind of _matrices_, or nourishing receptacles for some small Insect, just as I have found Oak-apples, and mult.i.tudes of such other large excrescencies on the leaves and other parts of Trees and shrubs to be for Flyes, and divers other Insects, but observing them to be there all the year, and scarce at all to change their magnitude, that conjecture seem'd not so probable. But what ever be the use of it, it affords a very pleasant object through the _Microscope_, and may, perhaps, upon further examination, prove very luciferous.

Observ. XXV. _Of the stinging points and juice of _Nettles_, and some other venomous Plants._

A Nettle is a Plant so well known to every one, as to what the appearance of it is to the naked eye, that it needs no description; and there are very few that have not felt as well as seen it; and therefore it will be no news to tell that a gentle and slight touch of the skin by a Nettle, does oftentime, not onely create very sensible and acute pain, much like that of a burn or scald, but often also very angry and hard swellings and inflamations of the parts, such as will presently rise, and continue swoln divers hours. These observations, I say, are common enough; but how the pain is so suddenly created, and by what means continued, augmented for a time, and afterwards diminish'd, and at length quite exstinguish'd, has not, that I know, been explain'd by any.

And here we must have recourse to our _Microscope_, and that will, if almost any part of the Plant be looked on, shew us the whole surface of it very thick set with turn-Pikes, or sharp Needles, of the shape of those represented in the 15. _Scheme_ and first _Figure_ by AB, which are visible also to the naked eye; each of which consists of two parts very distinct for shape, and differing also in quality from one another. For the part A, is shaped very much like a round Bodkin, from B tapering till it end in a very sharp point; it is of substance very hard and stiff, exceedingly transparent and cleer, and, as I by many trials certainly found, is hollow from top to bottom.

This I found by this Experiment, I had a very convenient _Microscope_ with a single Gla.s.s which drew about half an Inch, this I had fastned into a little frame, almost like a pair of Spectacles, which I placed before mine eyes, and so holding the leaf of a Nettle at a convenient distance from my eye, I did first, with the thrusting of several of these bristles into my skin, perceive that presently after I had thrust them in I felt the burning pain begin; next I observ'd in divers of them, that upon thrusting my finger against their tops, the Bodkin (if I may so call it) did not in the least bend, but I could perceive moving up and down within it a certain liquor, which upon thrusting the Bodkin against its basis, or bagg B, I could perceive to rise towards the top, and upon taking away my hand, I could see it again subside, and shrink into the bagg; this I did very often, and saw this _Phaenomenon_ as plain as I could ever see a parcel of water ascend and descend in a pipe of Gla.s.s. But the basis underneath these Bodkins on which they were fast, were made of a more pliable substance, and looked almost like a little bagg of green Leather, or rather resembled the shape and surface of a wilde Cuc.u.mber, or _cuc.u.meris asinini_, and I could plainly perceive them to be certain little baggs, bladders, or receptacles full of water, or as I ghess, the liquor of the Plant, which was poisonous, and those small Bodkins were but the Syringe-pipes, or Glyster-pipes, which first made way into the skin, and then served to convey that poisonous juice, upon the pressing of those little baggs, into the interior and sensible parts of the skin, which being so discharg'd, does corrode, or, as it were, burn that part of the skin it touches; and this pain will sometimes last very long, according as the impression is made deeper or stronger.

The other parts of the leaf or surface of the Nettle, have very little considerable, but what is common to most of these kinds of Plants, as the ruggedness or indenting, and hairiness, and other roughnesses of the surface or out-side of the Plant, of which I may say more in another place.

As I shall likewise of certain little pretty cleer b.a.l.l.s or Apples which I have observed to stick to the sides of these leaves, both on the upper and under side, very much like the small Apples which I have often observ'd to grow on the leaves of an Oak call'd _Oak-apples_ which are nothing but the _Matrices_ of an Infect, as I elsewhere shew.

The chief thing therefore is, how this Plant comes, by so slight a touch, to create so great a pain; and the reason of this seems to be nothing else, but the corrosive penetrant liquor contain'd in the small baggs or bladders, upon which grow out those sharp Syringe-pipes, as I before noted; and very consonant to this, is the reason of the pain created by the sting of a Bee, Wasp, &c. as I elsewhere shew: For by the Dart, which is likewise a pipe, is made a deep pa.s.sage into the skin, and then by the anger of the Fly, is his gally poisonous liquor injected; which being admitted among the sensible parts, and so mix'd with the humours or _stagnating_ juices of that part, does create an Ebullition perhaps, or _effervescens_, as is usually observ'd in the mingling of two differing _Chymical saline_ liquors, by which means the parts become swell'd, hard, and very painfull; for thereby the nervous and sensible parts are not onely stretch'd and strain'd beyond their natural _tone_, but are also p.r.i.c.k'd, perhaps, or corroded by the pungent and incongruous parts of the intruded liquor.

And this seems to be the reason, why _Aqua fortis_, and other _saline_ liquors, if they come to touch the sensitive parts, as in a cut of the skin, or the like, do so violently and intollerably _excruciate_ and torment the Patient. And 'tis not unlikely, but the Inventors of that Diabolical practice of poisoning the points of Arrows and Ponyards, might receive their first hint from some such Instance in natural contrivances, as this of the Nettle: for the ground why such poison'd weapons kill so infallibly as they do, seems no other then this of our Nettle's stinging; for the Ponyard or Dart makes a pa.s.sage or entrance into the sensitive or vital parts of the body, whereby the contagious substance comes to be dissolv'd by, and mix'd with the fluid parts or humours of the body, and by that means spreads it self by degrees into the whole liquid part of the body, in the same manner, as a few grains of Salt, put into a great quant.i.ty of Water, will by degrees diffuse it self over the whole.

And this I take to be the reason of killing of Toads, Frogs, Effs, and several Fishes, by strewing Salt on their backs (which Experiment was shewn to the _Royal Society_ by a very ingenious Gentleman, and a worthy Member of it) for those creatures having always a continual exsudation, as it were, of slimy and watry parts, sweating out of the pores of their skin, the _saline_ particles, by that means obtain a _vehicle_, which conveys them into the internal and vital parts of the body.

This seems also to be the reason why bathing in Mineral waters are such soveraign remedies for mult.i.tudes of distempers, especially chronical; for the liquid & warm _vehicles_ of the Mineral particles, which are known to be in very considerable quant.i.ties in those healing baths, by the body's long stay in them, do by degrees steep and insinuate themselves into the pores and parts of the skin, and thereby those Mineral particles have their ways and pa.s.sages open'd to penetrate into the inner parts, and mingle themselves with the _stagnant_ juices of the several parts; besides, many of those offensive parts which were united with those _stagnant_ juices, and which were contrary to the natural const.i.tution of the parts, and so become irksome and painfull to the body, but could not be discharged, because Nature had made no provision for such accidental mischiefs, are, by means of this soaking, and filling the pores of the skin with a liquor, afforded a pa.s.sage through that liquor that fills the pores into the ambient fluid, and thereby the body comes to be discharged.

So that 'tis very evident, there may be a good as well as an evil application of this Principle. And the ingenious Invention of that Excellent person, Doctor _Wren_ of injecting liquors into the veins of an Animal, seems to be reducible to this head: I cannot stay, nor is this a fit place, to mention the several Experiments made of this kind by the most incomparable Mr. _Boyle_, the mult.i.tudes made by the lately mention'd _Physician_ Doctor _Clark_, the History whereof, as he has been pleas'd to communicate to the _Royal Society_, so he may perhaps be prevail'd with to make publique himself: But I shall rather hint, that certainly, if this Principle were well consider'd, there might, besides the further improving of Bathing and Syringing into the veins, be thought on several ways, whereby several obstinate distempers of a humane body, such as the Gout, Dropsie, Stone, &c. might be master'd, and expell'd; and good men might make as good a use of it, as evil men have made a perverse and Diabolical.

And that the filling of the pores of the skin with some fluid _vehicle_, is of no small efficacy towards the preparing a pa.s.sage for several kinds of penetrant juices, and other dissoluble bodies, to insinuate themselves within the skin, and into the sensitive parts of the body, may be, I think, prov'd by an Instance given us by _Bellonius_, in the 26. _Chapter_ of the second Book of his _Observations_, which containing a very remarkable Story I have here transcrib'd: _c.u.m Chamaeleonis nigri radices_ (says he) _apud Pagum quendam Livadochorio nuncupatum erui curaremus, plurimi Graeci & Turcae spectatum venerunt quid erueremus, eas vero frustulatim secabamus, & filo trajiciebamus ut facilius exsiccari possent. Turcae in eo negotio occupatos nos videntes, similiter eas radices tractare & secare voluerunt: at c.u.m summus esset aestus, & omnes sudore maderent, quicunque eam radicem manibus tractaverant sudoremque absterserant, aut faciem digitis scalpserant, tantam pruriginem iis locis quos attigerant postea senserunt, ut aduri viderentur. Chamaeleonis enim nigri radix ea virtute pollet, ut cuti applicata ipsam adeo inflammet, ut nec squillae, nec urticae ullae centesima parte ita adurent: At prurigo non adeo celeriter sese prodit. Post unam aut alteram porro horam, singuli variis faciei locis cutem adeo inflammatam habere caepimus ut tota sanguinea videretur, atque quo magis eam confricabamus, tanto magis excitabatur prurigo. Fonti a.s.sidebamus sub platano, atque initio pro ludicro habebamus & ridebamus: at tandem illi plurimum indignati sunt, & nisi a.s.severa.s.semus nunquam expertos tali virtute eam plantam pollere, haud dubie male nos multa.s.sent, Attamen nostra excusatio fuit ab illis facilitus accepta, c.u.m eodem incommodo nos affectos conspicerent. Mirum sane quod in tantillo radice tam ingentem efficaciam nostro malo experti sumus._

By which observation of his, it seems manifest, that their being all cover'd with sweat who gather'd and cut this root of the black _Chameleon_ Thistle, was the great reason why they suffer'd that inconvenience, for it seems the like circ.u.mstance had not been before that noted, nor do I find any mention of such a property belonging to this Vegetable in any of the Herbals I have at present by me.

I could give very many Observations which I have made of this kind, whereby I have found that the best way to get a body to be insinuated into the substance or insensible pores of another, is first, to find a fluid _vehicle_ that has some congruity, both to the body to be insinuated, and to the body into whose pores you would have the other convey'd. And in this Principle lies the great mystery of staining several sorts of bodies, as Marble, Woods, Bones, &c. and of Dying Silks, Cloaths, Wools, Feathers, &c.

But these being digressions, I shall proceed to:

Observ. XXVI. _Of _Cowage_, and the itching operation of some bodies._

There is a certain Down of a Plant, brought from the _East-Indies_, call'd commonly, though very improperly, _Cow-itch_, the reason of which mistake is manifest enough from the description of it, which Mr. _Parkinson_ sets down in his _Herbal_, Tribe XI. Chap. 2. _Phasiolus siliqua hirsuta; The hairy Kidney-bean, called in _Zurratte_ where it grows, Couhage: We have had_ (says he) _another of this kind brought us out of the _East-Indies_, which being planted was in shew like the former, but came not to perfection, the unkindly season not suffering it to shew the flower; but of the Cods that were brought, some were smaller, shorter, and rounder then the Garden kind; others much longer, and many growing together, as it were in cl.u.s.ters, and cover'd all over with a brown short hairiness, so fine, that if any of it be rubb'd, or fall on the back of ones hand, or other tender parts of the skin, it will cause a kind of itching, but not strong, nor long induring, but pa.s.sing quickly away, without either danger or harm; the Beans were smaller then ordinary, and of a black shining colour._

Having one of these Cods given me by a Sea-Captain, who had frequented those parts, I found it to be a small Cod, about three Inches long, much like a short Cod of _French Beans_, which had six Beans in it, the whole surface of it was cover'd over with a very thick and shining brown Down or Hair, which was very fine, and for its bigness stiff; taking some of this Down, and rubbing it on the back of my hand, I found very little or no trouble, only I was sensible that several of these little downy parts with rubbing did penetrate, and were sunk, or stuck pretty deep into my skin.

After I had thus rubb'd it for a pretty while, I felt very little or no pain, in so much that I doubted, whether it were the true Couhage; but whil'st I was considering; I found the Down begin to make my hand itch, and in some places to smart again, much like the stinging of a Flea or Gnat, and this continued a pretty while, so that by degrees I found my skin to be swell'd with little red pustules, and to look as if it had been itchie. But suffering it without rubbing or scratching, the itching tickling pain quickly grew languid, and within an hour I felt nothing at all, and the little _protuberancies_ were vanish'd.

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 mult.i.tude 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.

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.

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.