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filament bends in such a plane, the consequent crowding together of the beads on the concave side is manifest.

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Fro. 8.—A portion of a filament in a convergent pencil. Fig. 4.—The same in a divergent pencil. In the latter case we may often see three or fonr dark inflective fringes,

instead of one only, as here indicated.

Now, if a filament at any part quits such a plane, the images of two or more portions of it, which may have afforded each other reflected and refracted rays, must be projected upon the same retinal spot; and considering that the filaments may cut the vertical transverse plane at every angle, that they may have every degree of tortuosity, are exceedingly plentiful, and the beads innumerable, the interference of their projections with one another must be of inconceivable frequency, and the resulting phenomena in all possible ways diversified. In such a case, it may be observed, it is neither the object which first intercepts a pencil of rays, nor that which last falls in their path, which is revealed by preference; as a rule, it is that whose image has the most forcible contrasts in bright and dark parts; in a divergent pencil, more commonly, though not necessarily, the hindmost object. Ordinarily neither image extinguishes the other, and even all the bright and dark spots of several such images may be distinguished at a retinal spot Yet events of another character may accrue: a couple of images may own a common centre, and coincide in their concentric fringes, generating an image of intensified contrasts. This effect is often produced if a filament bends sharply forwards. Again, the reverse of this happens by several images of beads dropping upon one another in such a fashion as to slur all the contrasts together, to their entire obliteration. Thus we have a continuous perfectly beaded thread severed into pieces, comprising many beads, but a few, or even single beads. By causing a fibre to twist in the eye, or by bringing the images of anterior beads of a fibre inclining forwards from the retina, over those of posterior ones, by aid of their different parallaxes when we move the focus of our exploring pencil from side to side, up and down, and as occasion requires, we may produce at pleasure phenomena of all the sorts that are here sketched.

Keeping, then, this hint in mind, and perseveringly disentangling the fibres, we may soon perceive that they arc all mere strings of beads, which coalesce by contracted surfaces. Here and there we may note some stouter than the rest, with perhaps their beads more broadly united, constituting, as it were, a stronger framework ramifying through the general web.

But it may be better to speak directly of what I find in my own eyes. I have, then, quite familiarized myself with the web—having a systemic but no further similarity to each other in my two eyes. I can at once locate in the tissue any thread that comes into view, and any globule that tumbles upon the sight I can restore to its place among the meshes of the web with facility. Again and again I have succeeded in stretching a host of seemingly disseminated beads into a tuft of neat fibres. And a number of them scattered separately among the meshes I have been able to distinctly assign to one or more crumpled fibres twined in among the rest. And if I have occasionally been unable to get a continuous inspection of certain fibres confined by others, I have dotted out their course satisfactorily by the line which the projected beads indicate. Whenever I have been able to cast a swarm of plain circular images tolerably free from coincident projections, I have not failed to discover that they are constituents of fibres. In all the examples of the anterior portion of the vitreous that fall within the reach of our convergent pencil, it is quite obvious that there is not a stray bead, and that all the fibres are series of beads.

Nevertheless, in the immense multitude I do fall in with some beads so involved among fibres, or so widely away from the axis of vision, as scarcely to afford an opportunity for the establishment of their being items in a series; and one or two beads, the nearest to the most sensible portion of the retina, where no contiguous ones are apparent, but which may be presumed to be merely displaying unusually strong images in a position where ordinary ones arc not discernible, and these are plainly held in their places in the fluid by some means or other. So that, from all these observations I feel all but absolutely certain that every bead forms a link in a fibre, and certain that there are no loose beads in the vitreous.

The net work, I see, is not a mere medley of fibres in a space of three dimensions. Arising thickly, but not indifferently, from over the surface of the hyaloid, they unite in detached groups, and the junction of these groups in the body of the fluid is not effected by fibres running in indiscriminate directions, but by fibres interlacing and anastomosing in such fashion as to form trellised sheets of tissue, some of the sheets being so replete with threads as to be almost a cloth of them, whilst others show them with considerable intervals.

Insomuch that these sheets, or fibrous lamella, are arranged like rudely latticed dissepiments, traversing dn a more or less continuous expansion the vitreous, with more freedom of movement as they reach further from its wall, along which they chiefly prevail, only extending into the interior obliquely, Bowman's account of the appearance of the vitreous body when prepared in chromic acid, involves a fair notion of what I am striving to convey. "A few concentric lamellae externally, to which succeed very irregular radiating septa, and lastly, an irregular central cavity." Only the word concentric must only import that from the extension of the kmellae near the wall, much of it takes a direction nearly parallel to it; the fibres run as if in the septa of a number * of cells, whose mean shape is expanded parallel to the parietes of the vessel, and compressed in a direction perpendicular to that, just as the elastic fibre of histologists is known to do in serous membranes, or homogeneous connective tissue, of which sort of fibre they would seem to be. These reticulated septa are woven, as it were, from the hyaloid, but span the orifice of the pupil without springing from the capsule of the crystalline. Nevertheless, no membrane is visible in the meshes, nor, could any homogeneous material of this sort be seen, if existing. Nor is there any granular deposit along or near the fibres to be seen, for what may wear a primd facie aspect of such, it is easy to detect, only proceeds from a peculiar overlying of the images of ordinary beads, which is often but transitory.

Such seeming, then, to be all the results obtainable by detailed inspection of the web, let us bring forward the observations on difference of specific gravity, which were left imperfectly interpreted, and try whether the unknown in the two cases may be arrived at by considering them together.

We shall hardly be inchued to conjecture that a fibre that looks precisely alike in all regions should be lighter than the vitreous fluid posteriorly, and heavier anteriorly, or that it, together with membrane in which it runs, is so. If thus, and the fluid freely communicates with itself throughout the vessel, when we look downwards the fibres in the vicinity of the lens would fall down upon it, and those near the retinal centre mount up against it. If the fibre runs in septa which completely divide the vitreous into shut cells, it might not be possible to refute the supposition before us, but its intrinsic improbability will prevent us from entertaining it .

In a former attempt to account for the see-saw motion from specific gravity, I suggested it might be attributable to an excess of light fibre in the back of the vitreous, overcoming the. buoyancy of that in the front, pulling down the less quantity, by a series of attachments of the expanded web to the hyaloid, as if over a line of pullcvs. But a renewed examination leaves me no room to think that any posterior excess exists, whilst in a freely communicating fluid the objection urged as fatal to the foregoing hypothesis applies equally well to this; and if the fluid be shut into separate bags, then, should we lie on the back, and incline the head but a little to one side, the strain of a posterior excess of buoyancy should fail to exert material force upon the anterior fibre; yet never can I witness any movement from gravity in one set of fibres without an equal opposite one in the other set. In a word, the endeavour to explain the see-saw phenomenon by imagining a difference in the specific gravities of the fibre and fluid, I feel compelled to abandon as a hopeless task.

However, it is left us to assume that the vitreous body is an aggregate of little bags which are filled with fluids of graduated density, the heavier in any two examples, always lying nearer the lens. The sole hypothesis which, as far as I can see into the matter, meets the requirements before us.

Fluids shut in lax bags admit a contortion of these sufficient to yield all the motions the web exhibits to us. With the optic axis in the horizon or inclined to it, the sinking of the heavier bags and rising of the lighter, would render the see saw phenomena with precision.

If we bend our gaze downwards, the heavier and lighter bags will tend, by their relative densities, to keep their places in the eye; and there does occur a certain dropping of the fibres running laterally from the centre of the retina, as if a bubble of fluid bounded by them were striving to reach the surface.

Should we look upwards, the heavier bags cannot descend, because they arc bound down on either side round the lens, and the lighter ones cannot ascend for a like reason; yet I think a certain direction of the lateral fibres indicates an arching upwards of the reticulated tissue near the middle of the retina in this case, whilst nice observation in this instance or the former may enable us to discern equivalent displacements of ;thc tissues spanning the lens. t

It seems immaterial for this hypothesis whether we regard those portions of the svitreous fluid removed from our easy inspection, most distant from the optic axis, to be kept in cells apart from that tn the middle portion, or not. But a lighter fluid may lie sover all parts of the retina, if rarer layers embrace each other from the lens towards the retina.

In this manner, then, I have been led to the conclusion that the vitreous body is a scompound concavo-convex lens, so constructed as in one respect to be a fluid imitation of the crystalline, a prolongation, as it were, of its series of posterior layers; which are formed of material of gradually diminishing refractive power, whilst the decreasing series is here inferred to bewcarried through the vitreous to the very retina, thus the middle of the crystalline is the centre of an easy succession of refractions, for the pencils of rays that are destined to impinge in foci upon the retina.*

(Ib be concluded in our next.)

* Though my earliest entoptlosl attempt In treating of the vltreoua was burdened with the defect of overlooking the anterior eross-current of musts, yet I will venture to qaote the words, la which it sums up, for comparison with the conclusions of other inquiries (London Med. Gas., vol xxxvt, p. 101): "The more I consider their connected chain-like character, their branches thrown out in so many different directions, and to such great lengths, the different parts of these figures changing their relative positions but very little, so that each mveca has, so to speak, a home In the vitreous, to which after each disturbance it finally returns, the more I feel disposed to regard them as fringes or processes of the hyaloid membrane, or as deposits in it s—that Is, in the septa of the cell-divided fluid." I owned myself puzzled swith these views to reconcile the obvious effects of the "vie inertia of the vitreous itself with the apparent st buoyancy " of the mveca. Brewator (paper citedi described both currents of mw«,va, termed the images dlffractive, and not refractive, offered a numerical retinal distance of a filament with "the diameter of its shadow," called them specifically lighter than the fluid, ignoring or overlooking all the anterior cross movements, except what arise from rotation,—took the beaded fibres for hollow tubes with scattered globules inside, perhaps "the remains of vessels," as existing in detached and floating portions"—In a word, these muec,e as fragmentary knotted fllamonts subject to increase and decrease within his experience, floating freely within a few cells with Invisible membranous walls, into which he divided the vitreous. As 1 learn form Helmholiz (Encyk, cit., s 158), who quotes them and adds his own sekiervatlons. Donders (Ncderlandsch Lancet 1846) and Duncan (De Corp. vltr. Struct . Dissert . Trajectl ad Ehextum, 1864) next investigate the vitreous, the latter of whom compares what he thus sees with what he observes under the microscope. The fine globules, (Donders) gradulatod threads {nit Kdrnern beeetei), aggregated granules (A*ornertuiufen\ and membranous-like folds "Isolated," or else attached to other forms or to the walls of the cavity, all of which are lighter than tho fluid,—register numerically the sizes and places of the objects. Finally, they like Brewster, regard what) they see as remnants of fcstal structure, but of the very internal framework of the vitreous, {dies Oebiide find Beit* dee embryonalen Bauee dee (rlaekdrpe/s). Afterwards I described all the objects of the vitreous as belonging to beaded fibres forming one system, and recognised the &ct that It is a relative movement from gravity of the anterior and posterior fibres that called for explanation. However it is quite enough to glance. Into the accounts of different observers to perceive that the contouts of the vitreous In all the individuals are ■like.

Art. II.

On the Treatment of Tetanus. By Campbell De Mor-an, Surgeon to the Middlesex

Hospital.

In a valuable report by Mr. Poland of "seventy-two cases of tetanus occurring in Guy's Hospital," published in the 'Guy's Hospital Reports,' the author adopts the view generally ontertained with regard to the efficay of remedies in this disease.

* "We can hardly," he observes, "call the medicines administered in the recoveries ' remedies;' they appear merely to have rendered the patient more able to fight against the battle of spasmodic action. Tetanus runs a certain course; it has its period of accession, its height and intense activity, and its gradual decline; it often kills before it reaches its active point; and often kills by exhaustion during its decline. Nothing seems to check its regular course; there is no control in its unvarying and undaunted career; it will have its sway. All we can do is to enable our patient to weather outvthe storm, by giving him as much strength as possible, and not adding fuel to the fire by all sorts of applications and internal remedies, which have over and over again signally failed."

This, which was the opinion of Hunter, and which is probably the opinion of most who have tried to combat this terrible disease, has been but too well justified by experience. But it is one which should not be pressed so far as to drive us to the conclusion that, because as yet there has been only failure, we must not look forward to success. On the contrary, should we not rather endeavour, by repeated experiment, to find some remedies from which positive results may be obtained? With a view to leading the profession to a more efficient trial of remedies, which, judging from the reported cases, have hardly as yet been fairly tested, the following case, with the observations upon it, has been drawn up:

Henry Blackwin, aged fifteen, employed at a coal shed, was admitted into the Middlesex Hospital on the 16th of September, 1858, with symptoms of trismus. He is short, but well formed and strong, and has had, by all accounts, very good health.

On the 30th of August, while walking, he trod on a large rusty nail, and the point of it pierced through the thin boot he had on, and ran into the right foot just at the base of the middle toe. There was little bleeding from the wound.

On the following day he came to the hospital, walking on the heel of the wounded foot in consequence of the pain, and aiding himself with a stick. A ponltice was ordered; a gathering formed in the part, which broke on the 4th of September, and the relief was so great that he was able to walk about. On the 7th the place was quite healed, and he discontinued his attendance. On the 8th he felt a stiffness about the jaw, which got so much worse that on the 12th he was unable to open his mouth. He felt some stiffness at the back of the neck, and pain down the back to such an extent as to interfere with his walking. He had some difficulty in swallowing. On the 13th he took to his bed. On the 15th he was unable to open his mouth or move his head, but he had no twitchings in his limbs. For two or three nights he had not had any sleep, but dozed off occasionally in the daytime. The bowels had beeen opened daily.

On the morning of the 16th he was brought to the Hospital; the trismus was very severe, and he was unable to move his head in any direction. He perspired freely, and complained of great pain down the back; but there was no opisthotonos. The abdominal muscles were very tense; pulse, eighty. He was ordered a castor-oil injection, and linseed-meal poultice down the back to which was added a lotion of chloroform, aconite, and opium. A draught containing paregoric and the liquor opii sedativus was given every six hours; broth diet and strong beef tea.

The injection only brought away a few scybala. At about ten P.m., on waking from a sleep of two hours, he had a spasm, which caused slight opisthotonos and great difficulty of breathing. The spasm lasted only a short time, and was followed by a copious perspiration. He slept afterwards for two hours.

17th. Feels more comfortable, is in less pain, and the expression of the face more natural.

Ordered: Olei tiglii, trj.j statim; tinct. aconiti, TTlv 3tiis horis; mist, vini gallici, 5 ij 4tis horis; essence of beef tea, two eggs, and milk Oj.

18th. Has had a fair night; but the trismus is more marked, and there is more pain down the back; the abdominal muscles are again very rigid. There is no pain in the foot.

He was in this condition when I first saw him on my return to town. Hitherto he had been under the care of my colleague, Mr. Flower. The symptoms since the morning had been more marked.and were gaining ground. For reasons hereafter mentioned, I ordered him at once the one-tenth of a grain of strychnine every two hoars, the symptoms to be carefully watched, and the medicine to be omitted so soon as any effects from it were observed. The diet to remain as before.

In the evening the muscles of the back were very rigid; he was unable to bend his knees, and there was from time to time slight opisthotonos. He complained of twitching* in the thighs, which- prevented his sleeping. These symptoms becoming more marked, the medicine was discontinued after the second dose.

19th, 1 P.m. The symptoms are more marked, the spasms at times being very severe, though during the night he had an hour or two of sleep. Ordered to resume the medicine.

10 P.m. The spasms have been increasing in severity. Hehashad six or seven violent paroxysms during the day, and has had continued suffering; pulse, one hundred and six; face and shoulders perspiring freely, The medicine to be taken during the night in half doses (one-twentieth grain of strychnine).

20th. Has had no continued sleep; on dozing off has been startled by violent spasms of the hands and arms; the body rigid throughout. This morning at about five had a paroxysm so severe that he was near death from asphyxia. He has great difficulty in swallowing. The pains down the thighs and in the abdominal muscles very severe. A turpentme enema to be used, and the strychnine to be given in its former dose, onetenth of a grain.

The enema acted well, but the spasms were increasing in frequency and violence. After the second dose the medicine was stopped; the pulse, one hundred and thirtyfive; the catchings in the hands constant.—Eleven P.m. The symptoms were now becoming so urgent that' the strychnine treatment could not be longer tried. It was evident that though it was producing its own specific effect, the paroxysms of the disease were in no way relieved, nor were the chronic spasms at all diminished.

That the symptoms were due in great measure to the disease was evident from the fact that the paroxysms did not correspond in time or severity with the administration of the strychnine. The symptoms increased in severity for fourteen hours during which no medicine was given; and at the time when the paroxysms were most severe, they became milder during periods when the medicine was still being given; whereas, when strychnine is the cause of similar symptoms, the fits correspond in time and severity with the reception of new portions of the poison. During the whole time, moreover, the chronic rigidity of the trunk and lower limbs was becoming progressively more intense.

The strychnine, therefore, was left off, and the patient was again put upon aconite, of which five minims of the pharmacopoeia tincture were given every two hours, and as the pains in the thighs were very severe, a liniment composed of equal parts of tinct. aconite and camphor liniment was directed to be rubbed into them.

21st. Has had some pretty severe attacks of spasm during the night, but says he feels more comfortable; the pains down the thighs are very acute. The whole body is still quite rigid. Has taken seven doses of the tincture, but feels no effect from it. It was ordered to be continued in eight minim doses; pulse, ninety. In the evening he complained of a feeling of soreness in the throat; otherwise, during the day, he had been freer from spasms. Ordered to take only half-doses (four minims) during the night

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