Micrographia Some Physiological Descriptions Of Minute Bodies M

Chapter 26

Chapter 263,972 wordsPublic domain

But to proceed; I observ’d several kind of hairs that had been Dyed, and found them to be a kind of horny _Cylinder_, being of much about the transparency of a pretty cleer piece of Oxe horn; these appear’d quite throughout ting’d with the colours they exhibited. And ’tis likely, that those hairs being boyl’d or steep’d in those very hot ting’d liquors in the Dye-fat, And the substance of the hair being much like that of an Oxes Horn, the penetrant liquor does so far mollifie and soften the substance, that it sinks into the very center of it, and so the ting’d parts come to be mix’d and united with the very body of the hair, and do not (as some have thought) only stick on upon the outward surface. And this, the boiling of Horn will make more probable; for we shall find by that action, that the water will insinuate it self to a pretty depth within the surface of it, especially if this penetrancy of the water be much helped by the Salts that are usually mix’d with the Dying liquors. Now, whereas Silk may be dyed or ting’d into all kind of colours without boiling or dipping into hot liquors, I ghess the reason to be two-fold: First, because the filaments, or small cylinders of Silk, are abundantly smaller and finer, and so have a much less depth to be penetrated then most kind of hairs; and next, because the substance or matter of Silk, is much more like a Glew then the substance of Hair is. And that I have reason to suppose: First, because when it is spun or drawn out of the Worm, it is a perfect glutinous substance, and very easily sticks and cleaves to any adjacent body, as I have several times observed, both in Silk-worms and Spiders. Next, because that I find that water does easily dissolve and mollifie the substance again, which is evident from their manner of ordering those bottoms or pods of the Silk-worm before they are able to unwind them. It is no great wonder therefore, if those Dyes or ting’d liquors do very quickly mollifie and tinge the surfaces of so small and so glutinous a body. And we need not wonder that the colours appear so lovely in the one, and so dull in the other, if we view but the ting’d cylinders of both kinds with a good _Microscope_; for whereas the substance of Hair, at best, is but a dirty duskish white somewhat transparent, the filaments of Silk have a most lovely transparency and cleerness, the difference between those two being not much less then that between a piece of Horn, and a piece of Crystal; the one yielding a bright and vivid reflection from the concave side of the cylinder, that is, from the concave surface of the Air that incompasses the back-part of the cylinder; the other yielding a dull and perturb’d reflection from the several _Heterogeneous_ parts that compose it. And this difference will be manifest enough to the eye, if you get a couple of small Cylinders, the smaller of Crystal Glass, the other of Horn, and then varnishing them over very thinly with some transparent colour, which will represent to the naked eye much the same kind of object which is represented to it from the filaments of Silk and Hair by the help of the _Microscope_. Now, since the threads of Silk and Serge are made up of a great number of these filaments, we may henceforth cease to wonder at the difference. From much the same reason proceeds the vivid and lovely colours of Feathers, wherein they very farr exceed the natural as well as Artificial colours of hair, of which I shall say more in its proper place.

The Teguments indeed of creatures are all of them adapted to the peculiar use and convenience of that Animal which they inwrap; and very much also for the ornament and beauty of it, as will be most evident to any one that shall attentively consider the various kinds of cloathings wherewith most creatures are by Nature invested and cover’d. Thus I have observed, that the hair or furr of those Northern white Bears that inhabite the colder Regions, is exceeding thick and warm: the like have I observ’d of the hair of a _Greenland_ Deer, which being brought alive to _London_, I had the opportunity of viewing; its hair was so exceeding thick, long and soft, that I could hardly with my hand, grasp or take hold of his skin, and it seem’d so exceeding warm, as I had never met with any before. And as for the ornamentative use of them, it is most evident in a multitude of creatures, not onely for colour, as the Leopards, Cats, Rhein Deer, _&c._ but for the shape, as in Horses manes, Cats beards, and several other of the greater sort of terrestrial Animals, but is much more conspicuous, in the Vestments of Fishes, Birds, Insects, of which I shall by and by give some Instances.

As for the skin, the _Microscope_ discovers as great a difference between the texture of those several kinds of Animals, as it does between their hairs; but all that I have yet taken notice of, when tann’d or dress’d, are of a Spongie nature, and seem to be constituted of an infinite company of small long _fibres_ or hairs, which look not unlike a heap of Tow or Okum; every of which _fibres_ seem to have been some part of a Muscle, and probably, whil’st the Animal was alive, might have its distinct function, and serve for the contraction and relaxation of the skin, and for the stretching and shrinking of it this or that way.

And indeed, without such a kind of texture as this, which is very like that of _Spunk_ it would seem very strange, how any body so strong as the skin of an Animal usually is, and so close as it seems, whil’st the Animal is living, should be able to suffer so great an extension any ways, without at all hurting or dilacerating any part of it. But, since we are inform’d by the _Microscope_, that it consists of a great many small filaments, which are implicated, or intangled one within another, almost no otherwise then the hairs in a lock of Wool, or the flakes in a heap of Tow, though not altogether so loose, but the filaments are here and there twisted, as ’twere, or interwoven, and here and there they join and unite with one another, so as indeed the whole skin seems to be but one piece, we need not much wonder: And though these _fibres_ appear not through a _Microscope_ exactly jointed and contex’d, as in Sponge; yet, as I formerly hinted, I am apt to think, that could we find some way of discovering the texture of it, whil’st it invests the living Animal, or had some very easie way of separating the pulp or intercurrent juices, such as in all probability fill those _Interstitia_, without dilacerating, brusing, or otherwise spoiling the texture of it (as it seems to be very much by the ways of tanning and dressing now us’d) we might discover a much more curious texture then I have hitherto been able to find; perhaps somewhat like that of Sponges.

That of _Chamoise_ Leather is indeed very much like that of _Spunk_, save onely that the _filaments_ seem nothing neer so even and round, nor altogether so small, nor has it so curious joints as _Spunk_ has, some of which I have lately discover’d like those of a Sponge, and perhaps all these three bodies may be of the same kind of substance, though two of them indeed are commonly accounted Vegetable (which, whether they be so or no, I shall not now dispute) But this seems common to all three, that they undergo a tanning or dressing, whereby the interspers’d juices are wasted and wash’d away before the texture of them can be discover’d.

What their way is of dressing, or curing Sponges, I confess, I cannot learn; but the way of dressing _Spunk_, is, by boiling it a good while in a strong _Lixivium_, and then beating it very well; and the manner of dressing Leather is sufficiently known.

It were indeed extremely desirable, if such a way could be found whereby the _Parenchyma_ or flesh of the Muscles, and several other parts of the body, might be wash’d, or wafted clean away, without vitiating the form of the _fibrous_ parts or vessells of it, for hereby the texture of those parts, by the help of a good _Microscope_, might be most accurately found.

But to digress no further, we may, from this discovery of the _Microscope_, plainly enough understand how the skin, though it looks so close as it does, comes to give a passage to so vast a quantity of _excrementitious_ substances, as the diligent _Sanctorius_ has excellently observed it to do, in his _medicina statica_; for it seems very probable, from the texture after dressing, that there are an infinite of pores that every way pierce it, and that those pores are onely fill’d with some kind of juice, or some very pulpy soft substance, and thereby the steams may almost as easily find a passage through such a fluid _vehicle_ as the vaporous bubbles which are generated at the bottom of a Kettle of hot water do find a passage through that fluid _medium_ into the ambient Air.

Nor is the skin of animals only thus pervious, but even those of vegetables also seem to be the same; for otherwise I cannot conceive why, if two sprigs of Rosemary (for Instance) be taken as exactly alike in all particulars as can be, and the one be set with the bottom in a Glass of water, and the other be set just without the Glass, but in the Air onely, though you stop the lower end of that in the Air very carefully with Wax, yet shall it presently almost wither, whereas the other that seems to have a supply from the subjacent water by its small pipes, or _microscopical_ pores, preserves its greenness for many days, and sometimes weeks.

Now, this to me, seems not likely to proceed from any other cause then the _avolation_ of the juice through the skin; for by the Wax, all those other pores of the stem are very firmly and closely stop’d up. And from the more or less porousness of the skins or rinds of Vegetables may, perhaps, be somewhat of the reason given, why they keep longer green, or sooner wither; for we may observe by the bladdering and craking of the leaves of Bays, Holly, Laurel, &c. that their skins are very close, and do not suffer so free a passage through them of the included juices.

But of this, and of the Experiment of the Rosemary, I shall elsewhere more fully consider, seeming to me an extreme luciferous Experiment, such as seems indeed very plainly to prove the _Schematism_ or structure of Vegetables altogether _mechanical_, and as necessary, that (water and warmth being apply’d to the bottom of the sprig of a Plant) some of it should be carried upwards into the stem, and thence distributed into the leaves, as that the water of the _Thames_ covering the bottom of the Mills at the Bridge foot of _London_, and by the ebbing and flowing of it, passing strongly by them, should have some part of it convey’d to the Cesterns above, and thence into several houses and Cesterns up and down the City.

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Observ. XXXIII. _Of the _Scales_ of a _Soal_, and other Fishes._

Having hinted somewhat of the skin and covering of terrestrial Animals, I shall next add an Observation I made on the skin and Scales of a _Soal_, a small Fish, commonly enough known; and here in Fishes, as well as other Animals, Nature follows its usual method, framing all parts so, as that they are both usefull and ornamental in all its composures, mingling _utile_ and _dulce_ together; and both these designs it seems to follow, though our unassisted senses are not able to perceive them: This is not onely manifest in the covering of this Fish, but in multitudes of others, which it would be too long to enumerate, witness particularly that small Sand Shell, which I mention’d in the XI. Observation, and infinite other small Shells and Scales, divers of which I have view’d. This skin I view’d, was flead from a pretty large _Soal_, and then expanded and dry’d, the inside of it, when dry, to the naked eye, look’d very like a piece of Canvass, but the _Microscope_ discover’d that texture to be nothing else, but the inner ends of those curious Scolop’d Scales I, I, I, in the second _Figure_ of the XXI. _Scheme_, namely, the part of GGGG (of the larger representation of a single Scale, in the first _Figure_ of the same _Scheme_) which on the back side, through an ordinary single Magnifying Glass, look’d not unlike the Tyles on an house.

The outside of it, to the naked eye, exhibited nothing more of ornament, save the usual order of ranging the Scales into a _triagonal_ form, onely the edges seem’d a little to shine, the finger being rubb’d from the tail-wards towards the head, the Scales seem’d to stay and raze it; But through an ordinary Magnifying glass, it exhibited a most curiously carved and adorned surface, such as is visible in the second _Figure_, each of those (formerly almost imperceptible) Scales appearing much of the shape I, I, I, that is, they were round, and protuberant, and somewhat shap’d like a Scolop, the whole Scale being creas’d with curiously wav’d and indented ridges, with proportionable furrows between; each of which was terminated with a very sharp transparent bony substance, which, like so many small Turnpikes, seem’d to arm the edges.

The back part KKK was the skin into which each of these Scales were very deeply fix’d, in the curious regular order, visible in the second _Figure_. The length and shape of the part of the Scale which was buried by the skin, is evidenced by the first _Figure_; which is the representation of one of them pluck’d out and view’d through a good _Microscope_, namely, the part LFGGFL, wherein is also more plainly to be seen, the manner of carving of the scolopt part of every particular Scale, how each ridge or barr EEE is alternately hollowed or engraven, and how every gutter between them is terminated with very transparent and hard pointed spikes, and how every other of these, as AAAA, are much longer then the interjacent ones, DDD.

The texture or form also of the hidden part appears, namely, the middle part, GGG, seems to consist of a great number of small quills or pipes, by which, perhaps, the whole may be nourished; and the side parts FF consist of a more fibrous texture, though indeed the whole Scale seem’d to be of a very tough gristly substance like the larger Scales of other Fishes.

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._

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.

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.

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.

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_._

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.

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.

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.

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.