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The Scales of the skin of a Dog-fish (which is us’d by such as work in Wood, for the smoothing of their work, and consists plainly enough to the naked eye, of a great number off small horny points) through the _Microscope_ appear’d each of them curiously ridg’d, and very neatly carved; and indeed, you can hardly look on the scales of any Fish, but you may discover abundance of curiosity and beautifying; and not only in these Fishes, but in the shells and crusts or armour of most sorts of _Marine_ Animals so invested.

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Observ. XXXIV. _Of the Sting of a Bee._

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The Sting of a _Bee_, delineated in the second Figure of the XVI. _Scheme_, seems to be a weapon of offence, and is as great an Instance, that Nature did really intend revenge as any, and that first, because there seems to be no other use of it. Secondly, by reason of its admirable shape, seeming to be purposely shap’d for that very end. Thirdly, from the virulency of the liquor it ejects, and the sad effects and symptoms that follow it.

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But whatever be the use of it, certain it is, that the structure of it is very admirable; what it appears to the naked eye, I need not describe, the thing being known almost to every one, but it appears through the _Microscope_, to consist of two parts, the one a sheath, without a chape or top, shap’d almost like the Holster of a Pistol, beginning at d, and ending at b, this sheath I could most plainly perceive to be hollow, and to contain in it, both a Sword or Dart, and the poisonous liquor that causes the pain. The sheath or case seem’d to have several joints or settings together, marked by fghiklmno, it was arm’d moreover neer the top, with several crooks or forks (pqrst) on one side, and (pqrstu) on the other, each of which seem’d like so many Thorns growing on a briar, or rather like so many Cat’s Claws; for the crooks themselves seem’d to be little sharp transparent points or claws, growing out of little _protuberancies_ on the side of the sheath, which, by observing the Figure diligently, is easie enough to be perceiv’d; and from several particulars, I suppose the Animal has a power of displaying them, and shutting them in again as it pleases, as a Cat does its claws, or as an Adder or Viper can its teeth or fangs.

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The other part of the Sting was the Sword, as I may so call it, which is sheath’d, as it were, in it, the top of which ab appears quite through at the smaller end, just as if the chape of the sheath of a Sword were lost, and the end of it appear’d beyond the Scabbard; the end of this Dart(a) was very sharp, and it was arm’d likewise with the like Tenter-hooks or claws with those of the sheath, such as (vxy, xyzz) these crooks, I am very apt to think, can be clos’d up also, or laid flat to the sides of the Sword when it is drawn into the Scabbard, as I have several times observ’d it to be, and can be spred again or extended when ever the Animal pleases.

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The consideration of which very pretty structure, has hinted to me, that certainly the use of these claws seems to be very considerable, as to the main end of this Instrument, for the drawing in, and holding the sting in the flesh; for the point being very sharp, the top of the Sting or Dagger (ab) is very easily thrust into an Animal’s body, which being once entred, the Bee, by endeavouring to pull it into the sheath, draws (by reason of the crooks (vxy) and (xyzz) which lay hold of the skin on either side) the top of the sheath (tsrv) into the skin after it, and the crooks t, s, and r, v, being entred, when the Bee endeavours to thrust out the top of the sting out of the sheath again, they lay hold of the skin on either side, and do not onely keep the sheath from sliding back, but helps the top inwards, and thus, by an alternate and successive retracting and emitting of the Sting in and out of the sheath, the little enraged creature by degrees makes his revengfull weapon pierce the toughest and thickest Hides of his enemies, in so much that some few of these stout and resolute soldiers with these little engines, do often put to flight a huge masty Bear, one of their deadly enemies, and thereby shew the world how much more considerable in Warr a few skilfull Engineers and resolute soldiers politickly order’d, that know how to manage such engines, are, then a vast unweildy rude force, that confides in, and acts onely by, its strength. But (to proceed) that he thus gets in his Sting into the skin, I conjecture, because, when I have observ’d this creature living, I have found it to move the Sting thus, to and fro, and thereby also, perhaps, does, as ’twere, pump or force out the poisonous liquor, and make it hang at the end of the sheath about b in a drop. The crooks, I suppose also to be the cause why these angry creatures, hastily removing themselves from their revenge, do often leave these weapons behind them, sheath’d, as ’twere, in the flesh, and, by that means, cause the painfull symptoms to be greater, and more lasting, which are very probably caus’d, partly by the piercing and tearing of the skin by the Sting, but chiefly by the corrosive and poisonous liquor that is by this Syringe-pipe convey’d among the sensitive parts thereof and thereby more easily gnaws and corrodes those tender _fibres_: As I have shewed in the description of a Nettle and of Cowhage.

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Observ. XXXV. _Of the contexture and shape of the particles of _Feathers_._

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Examining several sorts of _Feathers_, I took notice of these particulars in all sorts of wing-Feathers, especially in those which serv’d for the beating of the air in the action of flying.

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That the outward surface of the Quill and Stem was of a very hard, stiff, and horny substance, which is obvious enough, and that the part above the Quill was fill’d with a very white and light pith, and, with the _Microscope_, I found this pith to be nothing else, but a kind of natural _congeries_ of small bubbles, the films of which seem to be of the same substance with that of the Quill, that is, of a stiff transparent horny substance.

PG15491.B00837
Which particular seems to me, very worthy a more serious consideration; For here we may observe Nature, as ’twere, put to its shifts, to make a substance, which shall be both light enough, and very stiff and strong, without varying from its own establish’d principles, which we may observe to be such, that very strong bodies are for the most part very heavie also, a strength of the parts usually requiring a density, and a density a gravity; and therefore should Nature have made a body so broad and so strong as a Feather, almost, any other way then what it has taken, the gravity of it must necessarily have many times exceeded this; for this pith seems to be like so many stops or cross pieces in a long optical tube, which do very much contribute to the strength of the whole, the pores of which were such, as that they seem’d not to have any communication with one another, as I have elsewhere hinted.

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But the Mechanism of Nature is usually so excellent, that one and the same substance is adapted to serve for many ends. For the chief use of this, indeed, seems to be for the supply of nourishment to the downy or feathery part of the stem; for ’tis obvious enough in all sorts of Feathers, that ’tis plac’d just under the roots of the branches that grow out of either side of the quill or stalk, and is exactly shap’d according to the ranking of those branches, coming no lower into the quill, then just the beginning of the downy branches, and growing onely on the under side of the quill where those branches do so. Now, in a ripe Feather (as one may call it) it seems difficult to conceive how the _Succus nutritius_ should be convey’d to this pith; for it cannot, I think, be well imagin’d to pass through the substance of the quill, since, having examin’d it with the greatest diligence I was able, I could not find the least appearance of pores; but he that shall well examine an unripe or pinn’d Feather, will plainly enough perceive the Vessel for the conveyance of it to be the thin filmy pith (as ’tis call’d) which passes through the middle of the quill.

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As for the make and contexture of the Down it self, it is indeed very rare and admirable, and such as I can hardly believe, that the like is to be discover’d in any other body in the world; for there is hardly a large Feather in the wing of a Bird, but contains neer a million of distinct parts, and every one of them shap’d in a most regular & admirable form, adapted to a particular Design: For examining a middle ciz’d Goose-quill, I easily enough found with my naked eye, that the main stem of it contain’d about 300. longer and more Downy branchings upon one side, and as many on the other of more stiff but somewhat shorter branchings. Many of these long and downy branchings, examining with an ordinary _Microscope_, I found divers of them to contain neer 1200. small leaves (as I may call them, such as EF of the first Figure of the 22. _Scheme_) and as many stalks on the other side, such as IK of the same Figure, each of the leaves or branchings, EF, seem’d to be divided into about sixteen or eighteen small joints, as may be seen plainly enough in the Figure, out of most of which there seem to grow small long _fibres_, such as are express’d in the Figure, each of them very proportionably shap’d according to its position, or place on the stalk EF; those on the under side of it, namely, 1, 2, 3, 4, 5, 6, 7, 8, 9, &c. being much longer then those directly opposite to them on the upper; and divers of them, such as 2, 3, 4, 5, 6, 7, 8, 9, &c. were terminated with small crooks, much resembling those small crooks, which are visible enough to the naked eye, in the seed-buttons of Bur-docks. The stalks likewise, IK on the other side, seem’d divided into neer as many small knotted joints, but without any appearance of strings or crooks, each of them about the middle K, seem’d divided into two parts by a kind of fork, one side of which, namely, KL, was extended neer the length of KI, the other, M, was very short.

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The transverse Sections of the stems of these branchings, manifested the shape or figure of it to be much like INOE, which consisted of a horny skin or covering, and a white seemingly frothy pith, much like the make of the main stem of a Feather.

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The use of this strange kind of form, is indeed more admirable then all the rest, and such as deserves to be much more seriously examin’d and consider’d, then I have hitherto found time or ability to do; for certainly, it may very much instruct us in the nature of the Air, especially as to some properties of it.

PG15491.B00842
The stems of the Downy branches INOE, being rang’d in the order visible enough to the naked eye, at the distance of IF, or somewhat more, the _collateral_ stalks and leaves (if I may so call those bodies I newly described) are so rang’d, that the leaves or hairy stalks of the one side lie at top, or are incumbent on the stalks of the other, and cross each other, much after the manner express’d in the second Figure of the 22. _Scheme_, by which means every of those little hooked _fibres_ of the leaved stalk get between the naked stalks, and the stalks being full of knots, and a prety way dis-join’d, so as that the _fibres_ can easily get between them, the two parts are so closely and admirably woven together, that it is able to impede, for the greatest part, the transcursion of the Air; and though they are so exceeding small, as that the thickness of one of these stalks amounts not to a 500. part of an Inch, yet do they compose so strong a texture, as, notwithstanding the exceeding quick and violent beating of them against the Air, by the strength of the Birds wing, they firmly hold together. And it argues an admirable providence of Nature in the contrivance and fabrick of them; for their texture is such, that though by any external injury the parts of them are violently disjoyn’d, so as that the leaves and stalks touch not one another, and consequently several of these rents would impede the Bird’s flying; yet, for the most part, of themselves they readily re-join and re-contex themselves, and are easily by the Birds stroking the Feather, or drawing it through its Bill, all of them settled and woven into their former and natural posture; for there are such an infinite company of those small _fibres_ in the under side of the leaves, and most of them have such little crooks at their ends, that they readily catch and hold the stalks they touch.

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From which strange contexture, it seems rational to suppose that there is a certain kind of mesh or hole so small, that the Air will not very easily pass through it, as I hinted also in the sixth Observation about small Glass Canes, for otherwise it seems probable, that Nature would have drawn over some kind of thin film which should have covered all those almost square meshes or holes, there seeming through the _Microscope_ to be more then half of the surface of the Feather which is open and visibly pervious; which conjecture will yet seem more probable from the texture of the brushie wings of the _Tinea argentea_, or white Feather wing’d moth, which I shall anone describe. But Nature, that knows best its own laws, and the several properties of bodies, knows also best how to adapt and fit them to her designed ends, and whoso would know those properties, must endeavour to trace Nature in its working, and to see what course she observes. And this I suppose will be no inconsiderable advantage which the _Schematisms_ and Structures of Animate bodies will afford the diligent enquirer, namely, most sure and excellent instructions, both as to the practical part of _Mechanicks_ and to the _Theory_ and knowledge of the nature of the bodies and motions.

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Observ. XXXVI. _Of _Peacocks_, _Ducks_, and other _Feathers_ of changeable colours._

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The parts of the Feathers of this glorious Bird appear, through the _Microscope_, no less gaudy then do the whole Feathers; for, as to the naked eye ’tis evident that the stem or quill of each Feather in the tail sends out multitudes of _Lateral_ branches, such as AB in the third Figure of the 22. _Scheme_ represents a small part of about ¹⁄₃₂ part of an Inch long, and each of the _lateral_ branches emit multitudes of little sprigs, threads or hairs on either side of them, such as CD, CD, CD, so each of those threads in the _Microscope_ appears a large long body, consisting of a multitude of bright reflecting parts, whose Figure ’tis no easie matter to determine, as he that examines it shall find; for every new position of it to the light makes it perfectly seem of another form and shape, and nothing what it appear’d a little before; nay, it appear’d very differing ofttimes from so seemingly inconsiderable a circumstance, that the interposing of ones hand between the light and it, makes a very great change, and the opening or shutting a Casement and the like, very much diversifies the appearance. And though, by examining the form of it very many ways, which would be tedious here to enumerate, I suppose I have discover’d the true Figure of it, yet oftentimes, upon looking on it in another posture, I have almost thought my former observations deficient, though indeed, upon further examination, I have found even those also to confirm them.

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These threads therefore I find to be a _congeries_ of small _Laminæ_ or plates, as eeeee, &c. each of them shap’d much like this of abcd, in the fourth _Figure_, the part ac being a ridge, prominency, or stem, and b and d the corners of two small thin Plates that grow unto the small stalk in the middle, so that they make a kind of little feather; each of these Plates lie one close to another, almost like a company of sloping ridge or gutter Tyles; they grow on each side of the stalk opposite to one another, by two and two, from top to bottom, in the manner express’d in the fifth Figure, the tops of the lower covering the roots of the next above them; the under side of each of these laminated bodies, is of a very dark and opacous substance, and suffers very few Rays to be trajected, but reflects them all toward that side from whence they come, much like the foil of a Looking-glass; but their upper sides seem to me to consist of a multitude of thin plated bodies, which are exceeding thin, and lie very close together, and thereby, like mother of Pearl shells, do not onely reflect a very brisk light, but tinge that light in a most curious manner; and by means of various positions, in respect of the light, they reflect back now one colour, and then another, and those most vividly.

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Now, that these colours are onely _fantastical_ ones, that is, such as arise immediately from the refractions of the light, I found by this, that water wetting these colour’d parts, destroy’d their colours, which seem’d to proceed from the alteration of the reflection and refraction. Now, though I was not able to see those hairs at all transparent by a common light, yet by looking on them against the Sun, I found them to be ting’d with a darkish red colour, nothing a-kin to the curious and lovely greens and blues they exhibited.

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What the reason of colour seems to be in such thin plated bodies, I have elsewhere shewn. But how water cast upon those threads destroys their colours, I suppose to be perform’d thus; The water falling upon these plated bodies from its having a greater congruity to Feathers then the Air, insinuates it self between those Plates, and so extrudes the strong reflecting Air, whence both these parts grow more transparent, as the _Microscope_ informs, and colourless also, at best retaining a very faint and dull colour. But this wet being wasted away by the continual evaporations and steams that pass through them from the Peacock, whil’st that Bird is yet alive, the colours again appear in their former luster, the _interstitia_ of these Plates being fill’d with the strongly reflecting Air.

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The beauteous and vivid colours of the Feathers of this Bird, being found to proceed from the curious and exceeding smalness and fineness of the reflecting parts, we have here the reason given us of all those gauderies in the apparel of other Birds also, and how they come to exceed the colours of all other kinds of Animals, besides Insects; for since (as we here, and elsewhere also shew) the vividness of a colour, depends upon the fineness and transparency of the reflecting and refracting parts; and since our _Microscope_ discovers to us, that the component parts of feathers are such, and that the hairs of Animals are otherwise; and since we find also by the Experiment of that Noble and most Excellent Person I formerly named; that the difference between Silk and Flax, as to its colour, is nothing else (for Flax reduc’d to a very great fineness of parts, both white and colour’d, appears as white and as vivid as any Silk, but loses that brightness and its Silken aspect as soon as it is twisted into thread, by reason that the component parts, though very small and fine, are yet pliable flakes, and not cylinders, and thence, by twisting, become united into one opacous body, whereas the threads of Silk and Feathers retain their lustre, by preserving their cylindrical form intire without mixing; so that each reflected and refracted beam that composes the gloss of Silk, preserves its own property of modulating the light intire); And since we find the same confirm’d by many other Experiments elsewhere mentioned, I think we may safely conclude this for an Axiome, that wheresoever we meet with transparent bodies, spun out into very fine parts, either cleer, or any ways ting’d, the colours resulting from such a _composition_ must necessarily be very glorious, vivid, and cleer, like those of Silk and Feathers. This may perhaps hint some usefull way of making other bodies, besides Silk, be susceptible of bright tinctures, but of this onely by the by.

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The changeable colour’d Feathers also of Ducks, and several other Birds, I have found by examination with my _Microscope_, to proceed from much the same causes and textures.

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Observ. XXXVII. _Of the Feet of _Flies_, and several other _Insects_._

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The foot of a Fly (delineated in the first _Figure_ of the 23. _Scheme_, which represents three joints, the two Tallons, and the two Pattens in a flat posture; and in the second _Figure_ of the same _Scheme_, which represents onely one joint, the Tallons and Pattens in another posture) is of a most admirable and curious contrivance, for by this the Flies are inabled to walk against the sides of Glass, perpendicularly upwards, and to contain themselves in that posture as long as they please; nay, to walk and suspend themselves against the under surface of many bodies, as the ceiling of a room, or the like, and this with as great a seeming facility and firmness, as if they were a kind of _Antipodes_, and had a _tendency_ upwards, as we are sure they have the contrary, which they also evidently discover, in that they cannot make themselves so light, as to stick or suspend themselves on the under surface of a Glass well polish’d and cleans’d; their suspension therefore is wholly to be ascrib’d to some Mechanical contrivance in their feet; which, what it is, we shall in brief explain, by shewing, that its Mechanism consists principally in two parts, that is, first its two Claws, or Tallons, and secondly, two Palms, Pattens, or Soles.

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The two Tallons are very large, in proportion to the foot, and handsomely shap’d in the manner describ’d in the _Figures_, by AB, and AC, the bigger part of them from A to _dd_, is all hairy, or brisled, but toward the top, at C and B smooth, the tops or points, which seem very sharp turning downwards and inwards, are each of them mov’d on a joint at A, by which the Fly is able to open or shut them at pleasure, so that the points B and C being entered in any pores, and the Fly endeavouring to shut them, the Claws not onely draw one against another, and so fasten each other, but they draw the whole foot, GGADD forward, so that on a soft footing, the tenters or points GGGG, (whereof a Fly has about ten in each foot, to wit, two in every joint) run into the pores, if they find any, or at least make their way; and this is sensible to the naked eye, in the feet of a _Chafer_, which, if he be suffer’d to creep over the hand, or any other part of the skin of ones body, does make his steps as sensible to the touch as the sight.

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But this contrivance, as it often fails the _Chafer_, when he walks on hard and close bodies, so would it also our Fly, though he be a much lesser, and nimbler creature, and therefore Nature has furnish’d his foot with another _additament_ much more curious and admirable, and that is, with a couple of Palms, Pattens or Soles DD, the structure of which is this:

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From the bottom or under part of the last joint of his foot, K, arise two small thin plated horny substances, each consisting of two flat pieces, DD, which seem to be flexible, like the covers of a Book, about FF, by which means, the plains of the two sides EE, do not always lie in the same plain, but may be sometimes shut closer, and so each of them may take a little hold themselves on a body; but that is not all, for the under sides of these Soles are all beset with small brisles, or tenters, like the Wire teeth of a Card used for working Wool, the points of all which tend forwards, hence the two Tallons drawing the feet forwards, as I before hinted, and these being applied to the surface of the body with all the points looking the contrary way, that is, forwards and outwards, if there be any irregularity or yielding in the surface of the body, the Fly suspends it self very firmly and easily, without the access or need of any such Sponges fill’d with an imaginary _gluten_, as many have, for want of good Glasses, perhaps, or a troublesome and diligent examination, suppos’d.

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Now, that the Fly is able to walk on Glass, proceeds partly from some ruggedness of the surface: and chiefly from a kind of tarnish, or dirty smoaky substance, which adheres to the surface of that very hard body; and though the pointed parts cannot penetrate the substance of Glass, yet may they find pores enough in the tarnish, or at least make them.

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This Structure I somewhat the more diligently survey’d, because I could not well comprehend, how, if there were such a glutinous matter in those supposed Sponges, as most (that have observ’d that Object in a _Microscope_) have hitherto believ’d, how, I say, the Fly could so readily unglew and loosen its feet: and, because I have not found any other creature to have a contrivance any ways like it, and chiefly, that we might not be cast upon unintelligible explications of the _Phænomena_ of Nature, at least others then the true ones, where our senses were able to furnish us with an intelligible, rationall and true one.

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Somewhat a like contrivance to this of Flies shall we find in most other Animals, such as all kinds of Flies and case-wing’d creatures; nay, in a Flea, an Animal abundantly smaller then this Fly. Other creatures, as Mites, the Land-Crab, &c. have onely one small very sharp Tallon at the end of each of their legs, which all drawing towards the center or middle of their body, inable these exceeding light bodies to suspend and fasten themselves to almost any surface.
