NOTES FROM A Course of Lectures

398 great part muscular, have separated from each other. This been done, with

I

lining membrane, so conspicuous in wounds, is not seen in ulcerations, the previous inflammation having solidified the parts. Whenever then an opening in a bowel is not filled up by the internal coat, the edges must be brought together by ligature. A ligature placed around an intestine of a dog, cuts its way through, into the cavity; and if the animal should survive some months, the part which had been injured will not be easily discovered. When the wound in the intestine is small, and yet larger eversion of the

than it would be safe to leave to nature, a ligature should be applied firmly around the opening, which should be raised with a pair of forceps, so as to admit of its application. When the wound is larger, the edges should be brought together by the continuous suture in a parallel line. A common needle carrying a fine well-waxed silk-thread, is to be introduced

about half a line from the peritonseal edge of the opening, and brought out at the corresponding point on the opposite side, a knot on the end of the thread prevent.ing its slipping. The first stitch should be a line from the end of the wound, and the last should terminate with a knot at a similar distance. The stitches should not be tightened when made, but left loose until all are inserted, when they may be drawn close, one after the other, the cut edges being turned in by a probe, so that the peritonaeal surfaces may be in contact under the stitches, the divided edges being turned into the cavity of the bowel. It has been advised not to pass the needle through the mucous coat, but only through the strong areolar tissue connecting it with the transverse muscular coat. It is apprehended that if this could be accurately done, which may be doubted, the ligature might not ulcerate its way through to the cavity of the bowel. It is therefore better to pass the needle through all the coats, until further observations shall have been made on man on this point. .....

-

.

7. W hen an incised wound in the intestines is not supposed to exceed a puncture in size, or is less than a third of an inch in length, no interference should take place; for the nature and extent of the injury cannot always be ascertained, without the committal of a greater mischief than the injury itself. When the wound in the external part is made by an instrument not larger than one-third, or from that to half an inch in width, no attempt to probe, or to meddle with the wound, for the purpose of examining the intestine, should be permitted.

some

hope

of its

being beneficial ; and I

recommend it for the serious consideration of those who may hereafter have the management of such cases. 8. When the abdomen is penetrated, and considerable bleeding takes place, and continues, it becomes necessary to enlarge the open, and look for the wounded vessel. If the heemorrhage should come from one of the mesenteric arteries, or the epigastric, two ligatures are to be applied on the injured part. If it should be presumed that the enlargement of the wound and the search for the wounded vessel is not likely to be effected with advantage to the patient, the wound should be closed by suture, and a compress laid over it. If the bleeding should continue internally, and the wounded partbecome distended, and tense, the sutures may be in part removed to give relief. If the belly should become very painful, tense, and manifestly full after a punctured wound, and not tympanitic, the wound should be enlarged to allow the evacuation of the blood, which cannot in such quantity be absorbed. Extravasations of blood of a determinate quantity are not found to be diffused all over the surface, and between the convolutions of the small intestines, provided the person have outlived the period of extravasation, and may be readily evacuated provided the wound be sufficiently open. It may, when confined without an external opening, be absorbed, but it is more likely to give rise to suppurative inflammation, and the formation of matter requiring with it to be discharged by an opening made for the purpose. Cases of extravasation terminating in this manner, are very rare in our northern climate, where inflammation usually runs high in the first instance. That they do sometimes occur should not be forgotten, and that surgery should not be wanting to give its aid. The proper treatment of gunshot wounds of the belly is a subject for which we have not time, and I can only refer to my work on " Injuries of the Abdomen," where it is fully pointed out.

When the external wound is made by a somewhat broader and longer instrument, it does not necessarily follow that the intestine should be wounded to an equal extent; and unless it protrudes, or the contents of the bowel be discharged through the wound, in the first instance, the surgeon will not be warranted in enlarging the wound, to see what mischief has been done. For, although it may be argued that a wound four or more inches long has been proved to be oftentimes as little dangerous as a wound of one inch in length, most people would prefer having the smaller wound, unless it could be believed, from calculation, that the intestine was also injured to a considerable extent. Few surgeons, even then, would like to enlarge the wound, to ascertain the fact, unless some considerable bleeding, or a discharge of fsecal matter, pointed out the necessity for such operation; when there would beI reason for believing that the patient would have a better chance of recovery, after the application of a suture to the wounded artery, or bowel, than if it were left to Nature. If the first two or three hours have passed away, and the pain, and the firm, not tympanitic swelling in the belly, as well as discharge from the wound, indicate the commencement of effusion from the bowel, or an extravasation of blood, an enlargement of the opening alone can save the life of the patient, although the operation may probably be unsuccessful. It is not, however, on that account to be always laid aside, when the state of the patient offers even a chance of success. The external wound should be enlarged, the effused matter sponged up with a soft moist sponge, and the bowel or artery secured by a suture. When a penetrating wound, which may have injured the intestine, has been closed by suture, and does not do well, increasing symptoms of the inflammation of the abdominal cavity being accompanied by general tenderness of that part, and a decided swelling underneath the wound, indicating effusion beneath, and apparently confined to it, the best chance for life will be given by reopening the wound, and even augmenting it, if necessary, to such an extent, as will allow a evacuation of the contents of the bowel. It is a point ready in surgery which a surgeon should contemplate in all its beariugs. The proceeding is simple, little dangerous, and under such circumstances, can do no harm. I have seen instances in which it has been done, and others in which it might have

NOTES FROM

A

Course of Lectures Delivered at St. Thomas’s

Hospital.

BY GILBERT MACKMURDO, ESQ.

F.R.S.,

SURGEON TO THAT HOSPITAL, AND TO THE ROYAL LONDON OPHTHALMIC HOSPITAL.

(Reported by MR.

HOWARD HOLLAND

MACKMURDO.)

LECTURE XVI. On Preternatural States of the Iris; Glaucoma ; Cat’s

Eye; Myopia ; Presbyopia III Effects of the Habitual Use of Glasses; Physiology of Adjustment of the Eye to Different Dis. than Iris; tances ; VoluntaryPower Pebbles for Spectacles; Non-perception of Different Colour8 over

the

Glasses better

;

Hemeralopia and Nyctalopia; Hemiopia ; effect of Snow on the Eyes; Complementary Co1CYU1"s and Cause of the Phenomenon Advantage of Neutral-Tint Glasses. GENTLEMEN,-We have to consider first, this evening, different preternatural states or affections of the iris. Occasionally, patients are brought before us, who have no irides, or only one iris. The sight of the individual is generally very imperfect and weak; I have known instances of this peculiar deficiency at all ages, in the infant, the youth, and the adult; and I have also been informed by the friends of such patients, that others of the family were similarly affected. Sometimes the iris will exist tolerably perfect in one eye, and not at all in the other; or an imperfect iris may be noticed in each eye. Intolerance of any strong light, as well as indistinct vision, almost always accompanies these defects in formation. I have not seen these patients suffering from cataracts, but several such cases have been recorded. Two brothers and a sister, all under ten years of age, were brought to me some time since, thus affected; they were very short-sighted, and even that myopic vision was indistinct. We see more frequently a defect of the iris, to which the name of coloboma iridis has been given, wherein the pupillary margin is, as it were, abruptly broken through. This presents many varieties. The most common one is, where this deficiency is at the lowest and middle part

399

pupil; and it appears, then, as if there were that no operation would have benefited Bourdelot, and he fluid proceeding from the pupil downwards then gave the name of glaucoma to this peculiar state of the the front of the iris. We also often notice a difference vitreous humour, and this opinion was very generally adopted; in the colour of a person’s irides, without his having suffered but several years since, Dr. Mackenzie, in his most excellent from inflammatory action. This should be always recollected, treatise, entered very fully into this subject. He had dissected inasmuch as a change of colour in the iris is generally men- several eyes thus affected, and found that the crystalline lenses tioned by us as one of the characteristics of iritis. I have a were generally of a yellow, yellowish-red, or reddish-brown patient now with this peculiarity in one eye, and in her case colour, and chiefly so towards the centre. They were of a. but the vitreous the lens is also opaque; she does not know what was the cause firm consistence, and generally of this change in the colour of her iris, and it appears to have humour was colourless, or yellowless, and very fluid. The taken place as insidiously as did the formation of cataract, and hyaloid membrane, in all the cases he examined-and this is without any suffering. I have also seen the iris spotted an important fact-had been destroyed by disease. The variously in both sound and unsound eyes, so that, of itself, it choroid was of a lightish-brown colour, and had very little does not seem to be a characteristic of disease; and yet the pigment on it; and finally, the retina presented no trace of friends of patients will point out these appearances with great limbus luteus, or of the so-called central foramen. But what are the symptoms and appearances in such casesz dismay, thinking them indicative of serious mischief. There is a condition of the iris termed myosis, wherein the pupil is Circum orbital or even frontal pain is generally first comexceedingly contracted; in these cases the iris contracts very plained of, and a general dimness of sight; the pupil has a. slowly, if at all; this usually occurs in weak or unhealthy greenish or yellowish-green appearance; and I recollect giving persons, but it also occurs in healthy individuals after long- you, on another evening, Mr. Tyrrell’s description of it-viz., continued use of the eyes in minute objects. The sight is that you seemed to be looking at the reflexion of the sun in generally weak, and very often frontal and circum orbital pains a muddy pool of water. Others have described the appearance are complained of. Different authorities have spoken of two to be that of a bright piece of yellow metal, situated at the forms of this condition of the iris-viz., of a paralytic and of a back of the eye. The vision gradually becomes worse, and the yellowish-green appearance is then more evident, and spasmodic myosis. You are aware, I suppose, that the pupil is contracted, and secondary cataract often forms. I am now speaking of turned upwards and inwards during sleep; it is also contracted chronic, and not of acute, glaucoma, to which I have at under full doses of opium. The contracted pupil, which results another time referred. The iris becomes sluggish in its from close occupation on minute objects, or with powerful glasses, motions, the pupil is dilated, and the retina eventually is inis seldom overcome by treatment; it becomes permanent, and sensible to light; there is, from the first, a general cloudiness we term it the pin-hole pupil. In some persons, however, of the humour, rendering it difficult to decide where the disis principally situated; the globe of the eye is very hard vision remains very distinct under these circumstances. When there are pains present, such as I have alluded to just now, or and tense in most instances, and this is supposed to result from where the general health of the patient has suffered, some an excessive secretion of vitreous humour. The patients will, improvement may be effected by a judicious plan of treat- moreover, complain of muscse of various kinds, also of numement, and entire rest of the eyes. We term the reverse con- rous ocular spectra, and of sparks of fire darting across their dition, mydriasis. This dilated condition of the pupil gene- eyes; and the retina is then seriously implicated also. rally accompanies some form of amaurosis. In some cases we Sometimes the pupils are not dilated, and then it is more diffigain much credit by advising patients to use spectacles, of cult to distinguish between this disease and cataract; but if which the frame is fitted with two pieces of black wood, having you dilate the pupil, by the application of belladonna, the a small circular hole at their centres. This plan would of greenish-yellow appearance will at once decide that it is not, at any rate, a simple cataract, capable of being benefited by course not succeed if amaurosis existed. There is much doubt as to the real causes of these opposite an operation. The sight seems to be injured by the state of conditions of the pupil; but we cannot avoid associating them the retina, by the absence of the pigment, and thirdly, by the with an unhealthy state of the nerves of the eye. We apply lens being partially dark. Cataracts may form, in these cases, stimulating applications and counter-irritants, and attend to either slowly or suddenly. The arteria centralis retinae, which the general health of the patients. In some cases we observe passes to the capsule, is affected by the destruction of the the pupil becoming gradually diminished; in others, we are hyaloid membrane, and hence the opacity of the capsule and disappointed. Venesection, in some few instances, may be lens. I have seen, in such cases, a lens fall suddenly to the beneficial, but in the majority I think it would be found very bottom of the globe, when the capsule has been lacerated; disadvantageous. The exhibition of ammonia, valerian, and and in other cases I have seen the lens float about for months, or even years, after such an operation, giving rise, in some the application of electricity, has been found of use. We often observe patients’ irides tremulous, and we are in cases, but not always, to much pain and internal irritation. the habit of assuming that the vision is somewhat imperfect This disease is generally met with in elderly persons, and in such cases; I have, however, seen several instances wherein some authorities consider that indulgence in tobacco, or I could not detect any failure in the sight. You will notice spirit-drinking, induces it; and the most melancholy consideration is this-that we know of no cure for it when it is an undulation of the iris in these cases, in very various degrees, and at different times; and the same patient may present to at all far advanced. We apply counter-irritants, and we give our view either a tolerably steady iris, or one which flaps forcalomel and opium, from the knowledge of their great utility wards and backwards like a loose sail. In some cases (and in all inflammatory conditions of the eye; and we enjoin rest particularly in one now under my care) the pupil will contract of the organ in every sense of the word. If we see the case and dilate well, and, also, the patient sees well, yet the irides in an early stage, a continuous antiphlogistic plan of treatment are thus unsteady; but these instances are certainly the exmay be very advantageously pursued. Whilst speaking of glaucomatous diseases, and of the pecuceptions to the general rule. We do not generally observe any change in the appearance of the irides themselves. This liarly bright appearance at the back of the eye, I may mencondition often follows the extraction of a cataract, and par- tion that the celebrated Beer seemed to have included, under ticularly in cases wherein the hyaloid membrane has been the name of cat’s eye, the silvery reflexion in the eyes of old diseased, and the vitreous humour was thus less confined, and people, and also that appearance which we observe occahaving escaped during the operation, in greater or less quan- sionally in children, resulting from the scrofulous and nontity, had been replaced by aqueous humour. In such cases, malignant depositions at the back of the eye, so well described almost every time the patient turns his eye from side to side, by the late Mr. Tyrrell, and which I have already spoken of; the iris will flap forwards or backwards, as I just now described, the vision is not always though frequently impaired in these The reflection is first observed when the infant is excases. and with these patients the vision is seldom good. The disease termed glaucoma has been referred to by met in posed to a moderate light at some distance from him, and when It was formerly described as a disease of the observer stands near the light, and a little on one side. a previous lecture. lens, and subsequently of the vitreous humour. Mr. Tyrrell supposed that this affection existed in the choroid, The former opinion, which was long held, was upset, according or between it and the retina. Some of the cases which I obto Dr. Mackenzie, by Brisseau, who had in a great measure served with him were not at all benefited by treatment, and formed his opinion in consequence of the dissection, by some few others appeared to be improved by a continued Marèchal, of the eyes of Bourdelot, physician to Louis XIV. mercurial course. A very intelligent young surgeon, (Mr. This physician having become blind, had left orders that his Cumming,) who was a pupil at our Ophthalmic Hospital when eyes should be examined after his death. He had cataracts; these cases were under our notice, subsequently wrote a paper but the vitreous humour was found to be of a yellowish on this subject, which was read at the Medico-Chirurgical colour; and reasoning chiefly on this case, Brisseau concluded Society, in which he stated his opinion that the sound human. of the edge of the

drop of black

a over

transparent,

ease

the crystalline

400 of the left as being the more frequently affected. I have seen was equally luminous with that of the dog or cat, if examined under favourable circumstances. His paper is an in- young children occasionally short-sighted, and I have known, teresting one, and I should recommend your perusing it, as it as I just now mentioned, persons become short-sighted after is published in the Society’s Transactions. From his experi- illnesses. Many very curious investigations have been made ments, he came to the conclusion that the reflection was in the respecting the classes of persons in whom myopia chiefly ex. choroid with its pigment, as the principal reflecting structure, isted. The late Mr. Ware found that out of 10,000 soldiers in and became increased in effect by the light returned from the the Guards, this affection was scarcely known, and that at the retina and the concavity of the hyaloid body; and with regard Military School at Chelsea, where there were upwards of to Beer’s assurnptions, Mr. Cumming concluded that he was 1300 children, not one had ever complained of myopia until Speaking of the reflection in a healthy eye at one time, and at Mr. Ware mentioned it, and then only three could be found another of cases in which the lymph had been deposited on who seemed really myopic. Now for the reverse : at the two the retina, and had presented the bright metallic appearance, universities of Oxford and Cambridge, myopia appeared very and that this mere luminosity of the retina is in no case a common, and in one college in which there were only 127 sign of an altered condition. There is in the power of vision members, thirty-two used glasses, double or single ! ! and if healthy eyes a great difference as to the distance we direct our attention to where hard study is so common, we at which individuals can read with comfort and distinctness, find that the comparative numbers of myopic persons is greatly and hence the terms myopia or short-sightedness, and pres- larger than in agricultural districts. I believe that close byopia or far-sightedness. Healthy persons generally read reading and attention to minute objects in other ways, as in distinctly at a distance varying from twelve to twenty different trades, does really induce myopia; this fact has been print inches. If it is necessary to bring the book nearer than six ascribed to the loss of power and adjustment as to distance, or eight inches, they are termed myopic; and, on the con- for the persons to whom I have just referred have been con. trary, a person is styled presbyopic when he finds it necessary tinually employing their eyes on near objects, and they appear to remove it farther from him than he had been accustomed to have lost all distinct vision of distant objects; and vice versa. previously to do. Myopia may arise from a loss of adjusting I have often noticed persons who have been much occupied power, or from an original imperfection in some of the refrac- in looking at distant objects, lose all accurate vision when extive media; the cornea or the lens may be too convex, or the amining near objects, and this condition seemed to last until vitreous humour may be excessive in quantity, or these parts they had again practised their eyes in looking at near objects may one or all be preternaturally dense. Near-sighted per- for a considerable time. I think Mr. Ware was quite correct sons see better in partial darkness than those who have more in his opinion, that members of the lower classes, who had perfect sight, as they are accustomed to bring objects close to not the means for procuring, or the temptation of fashion to their eyes, and therefore receive the advantage of all the use, concave glasses, and yet who really were in early life light which proceeds from it. Thus also they frequently write to a certain degree myopic, have gradually improved in this a very small but clear hand, the very small letters appearing respect by the constant use of their unassisted eyes. I hav6 clear and distinct to them, from the fact of their proximity long known two brothers, who when they were boys comincreasing the visual angle subtended by them. Thus also if plained of their sight, and appeared each of them to be somethey look through a minute hole, they can distinguish objects what myopic. One of them, a smart, conceited lad, at once clearly at a greater distance than before, the circumferential adopted, and has always used, glasses, and now he is obliged rays being excluded, which would by their early convergence to use very concave ones at all times. The other was at once have formed a focus before they reached the retina; and they persuaded by his friends to give up the glass he had just progenerally half close their eyes when looking at any distant cured, and he has gradually become strong-sighted, and reads object, and their pupils, which are always large, receive then with his book at the regular distance with ease. As regards the treatment of myopia, from what I have said only the direct rays. Children who have long suffered with strumous ophthalmia you will perceive that if there is any indication for medicine, often become myopic. They have had, perhaps, strumous you should at once have recourse to it; and, on the other corneitis, and most probably some part has been left more hand, correct or alter the habits and occupation of the patients, dense, and hence the myopia, or it arises sometimes in such as circumstances shall indicate. I might relate to you many distressing cases, had we time, cases from an increased depth in the anterior chamber of the strumous ophthalmia ; also where hydrophthalmia has ex- of the results of the early indulgence in concave glasses, and isted, persons become thus affected. The anterior chamber in the unfortunate practice of increasing their power without seems in some of these cases to be enlarged, because the cornea any necessity, or of using them constantly. It is very imhas become thinned behind; sometimes the iris also appears portant, when any glasses are to be allowed, that the lowest to have fallen backwards, and in other cases forwards. The power should be given with which the patient can see objects disease, called conical cornea,which I have previously described, distinctly at a proper distance, and that spectacles, or at any will produce this defect, and as it advances, the vision becomes rate double glasses, should be procured, and not single ones. seriously interfered with, as the cornea becomes much thinned This precaution being adopted, it is very possible the patient posteriorly; and a case is related by Mr. Wardrop in which may never be obliged to increase the power he has commenced the apex of the cornea was burst by an accidental blow on the with, and sometimes even a lower power may subsequently eye with a lash of a whip. When I was speaking the other prove sufficient, although the eyedoes not become less myopic evening of congenital cataracts, I told you that I had known from mere age, as has been generally supposed. We hear of persons who had grown up suffering under congenital the division of one or more, or even of all the recti muscles, cataracts, and who had been supposed to suffer only from for the cure of myopia, on the plea of their exercising pressure myopia, or weak sight. I have now three such persons under on, and thus elongating, the eyeball. M. Guerin, of Paris, and my care, who when they came to me thought they had only M. Bonnet, of Lyons, and others, have advocated this treatweak or short sight, whereas they have imperfectly opake ment. I agree with those who think the proposed remedy lenses, and I have reason to believe that their semi-dark con- would be much worse than the defect they wish to cure. dition has existed from their earliest childhood. Patients Opticians inform us that patients who use a concave glass for apply to us for the cures of their short sight, ascribing their one eye only, have frequently been obliged to increase the condition to very various causes, as, for instance, to the exis- power, but that this does not occur when spectacles are used. The opposite condition to that which we have been now tence of worms in the intestines, to sudden chills, to fits, &c. &c., and it appears that they are often correct, for they are in considering is presbyopia, or far-sightedness; as we advance many instances much improved by attention being given to in years, the refractive power becomes weakened, or the axis their statements. Physiologists have differed much on the of the eye becomes too short, and consequently the rays of question as to myopia being the result merely of over-refrac- light are not brought sufficiently soon to a focus, which is tion, or being the result of a deficiency in the accommodating now situated behind instead of on the retina; but we still power of the eye to different distances. I cannot agree with see very distant objects tolerably well, as the rays prosome very high authorities, who maintain that myopic persons ceeding from them require a less refractive power to bring This condition occurs at possess the same power of varying the quantity of refraction them to a focus on the retina. as other individuals. Every accurate observer knows that the various ages-we expect it between the ages of forty and two eyes of different persons frequently differ in their refrac- forty-five, but we do occasionally see it at a very early age, tive power, and accidental circumstances alone have informed and, on the contrary, persons have lived to upwards of 100 such parties of the imperfection or even loss of one of their in the enjoyment of excellent sight. I have known one case eyes. I have not observed that myopia is more prevalent in of an old woman, who threaded her needle and darned her one eye than the other, but different surgeons have varied in stockings, &c., when upwards of 100 years of age : she their opinion on this point; some speak of the right and some never used spectacles, and could read her Bible easily at that

eye

of different

401 and I have known many who have not required glasses when upwards of eighty years of age. The most common Complaint to us by our presbyopic patient is, that he cannot read small print, snuff the candle, or mend his pen, and that he is obliged to hold his book at a greater distance from him, and hold the candle, if at night, between his eye and the book, or paper; or that the letters are confused and run into each other; and that he cannot see otherwise, accurately. You give him a slightly convex glass, and he is delighted. I said that the refractive power becomes weakened by age; and we appear also to lose the power of accommodating our eye to near objects. When persons are thus affected, if they persevere in reading small print, or examining near objects, they soon feel a heavy sensation in the forehead and brow, amounting almost to pain. It is supposed that a diminution in the quantity of the vitreous and aqueous humour dependent on increasing age, is a partial cause of presbyopia, as also the usually increasing density of the lens, which at the same time becomes flattened. We hear of cases in which persons who have used convex glasses for many years have suddenly recovered the use of

time;

their sight at eighty or ninety; and Mr. Ware stated that such persons have discontinued the use of their glasses altogether. I have not seen any such instances, but I would not for an instant throw a doubt on the truth of such a statement. He thought that the sclerotic was pressed on laterally by the muscles after some of the vitreous humour had been absorbed, and thus the axis of the eye was lengthened. I have known young children become presbyopic after illnesses; but in every case I have treated, this condition of the eye has been only temporary, and as the child recovered its health and strength, the eyelost its presbyopic vision. The power of adjustment has been at different times attributed to many different causes, some of which I have referred to, as the change in the cornea, or the pupil, or of the lens itself; by the action of the ciliary body, or of the sclerotic by pressure on the muscles. One of the investigators on this subject is my colleague, Mr. Bowman, whose lectures I have already strongly recommended to your study. He thinks that the "ciliary muscle," as he styles that which is generally called the" ciliary circle," may possibly be destined to advance the lens, by drawing the ciliary processes towards the line of junction of the sclerotic and cornea, and that it may at the same time exercise some pressure on the vitreous body.* The same opinion is now held by many others, and Professor Owen has made some excellent remarks on the subject, in the article " Aves," in the " Cyclopaedia of Anatomy and Physiology." He states that he considers the marsupium as an erectile organ, adapted to receive a varying quantity of blood, and thus occupy a variable space in the vitreous humour; when fully injected it would tend to push the lens forwards directly by the intervention of some of the thus displaced vitreous humour, and that the contrary effects will ensue when the vascular action

is diminished. In one of my early lectures, I mentioned the case of Dr. Roget, as related by himself, in a letter to Mr. Travers, who published it in his interesting Synopsis of the Diseases of the Eye," nearly thirty years ago; and also of the late Dr. Miller, as bearing on this point of adjustment of the eye. I

must not here enter much farther into the subject, and I would thereforerefer you to Dr. Roget’s most interesting letter, in which he speaks of his power of dilating and contracting the iris at pleasure. He states that he can, whilst steadily directing his eyes to a distant object, and while no other object intervenes, by a mere effort of volition exerted on his eye, augment its refractive power, so as to adapt it to the vision of near objects; and he ascribes this power to his having been for many years much occupied in observing optical phenomena, and practising different experiments relating to vision. Dr. Miller possessed this power to a great degree, and I often saw him exercise it. His pupils became alternately contracted and dilated during such efforts. Mr. Ware and others have published several cases, in which presbyopic persons become myopic, and the reverse, during the treatment for severe ill-

nesses ;

some

of these

changes

were

permanent, others only

temporary. Many persons have been induced to use convex glasses of a low power when they did not need them, because Since these lectures were delivered, a paper has been communicated to the Royal Society, by Mr. Rainey, of St. Thomas’s Hospital, in which is contained a description of a muscle of the striped variety, lining about the posterior two-thirds of the choroid coat of the eye, in mammals. On the action of the muscle upon the lens, through the medium of the vitreous humour, the power possessed by the eye of adapting itself to distinct vision at different distances is shown to depend.

they had heard them called preservers; whilst others, who really needed some assistance, have, from vanity, or fear of creating a necessity, not adopted the use of convex glasses, when their eyes have really stood in need of such aid; and there is also an incorrect opinion prevalent, that pebbles are much superior to glasses. They are, indeed, harder, and are worked with more difficulty, and are much more expensive, if that is an advantage; but they are not so correct, generally,

from their very nature; and I would advise those who are sceptical on these points to go to any skilful optician, who will very soon convince them of their error, although, as Mr. Hawes very truly says, " it is not a piece of information so advantageous to the vendor as to the purchaser." By experiment, it has been found that the cornea is occasionally irregular : of course this has occasioned irregular refractions, and a multiplication or confusion of images. Professor Airey and M. Prevost have each published accounts of their own cases, as exemplifying this fact. Also many persons labour under an insensibility to certain colours; the being only capable of distinguishing white from black is the more common peculiarity ; others have been unable to distinguish pink or red colours; and authors who have collected many cases of these peculiar defects, and who have written on the subject, inform us that the chief peculiarities in such persons are the confounding red with green, and pink with blue, and that red light, and colours in which it forms an ingredient, and its accidental colour, are not distinguishable by these persons; a red appears dark, and a green appears drab; and yellow and blue, which appear to them the opposite colours, are the only Dr. Priestley, in a paper ones they can distinguish correctly. on this subject in the Philosophical Transactions, mentioned many cases, and amongst them, that of a shoemaker, who called all bright tints white, and all dull tints black; also the case of the artist, whose companions amused themselves by putting his colours out of order, and that he very innocently afterwards gave a gentleman a green beard, and painted a lady with blue cheeks. The celebrated Dr. Dalton suffered under this defect, and he had an idea that the humours of his eye were coloured blue, and therefore absorbed a great proportion of the red and other least refrangible rays, as he could only distinguish in the solar spectrum yellow, blue, and purple; and he said he could not see any difference between his own professional red gown and the green trees. His eyes were examined after his death, and did not present the peculiarity he had predicted, or, indeed, any other. Many similar cases are recorded. Although this defect in the power of recognising colours has been very generally supposed to be a congenital condition, cases are mentioned, in which it has followed irregular habits and excessive drinking. Mackenzie mentions a case, in which a patient thus affected said he saw objects farther in the dark than any of his acquaintances. Many theories have been broached as to the cause of this state. Brewster conceived that the eye, in such cases, was insensible to the colours at the end of the spectrum. Darwin and Young thought that the retina was active, generally, and that certain filaments were, in these cases, paralyzed; and Sir John Herschel considered that the sensorium itself was in fault, and that it had become incapable of appreciating exactly those differences between rays, on which their colour depends. Phrenologists quote many such cases, and attribute the defect to the non-development of the organ of colour in the brain. I knew Drs. Gall and Spurzheim well, and their opinions were very decided on this point. Photopsia and ocular spectra are often very annoying to patients; the first often occurs under amaurotic affections, or sometimes as the result of pressure from small tumours on the eye itself; the latter, the ocular spectra, occur, with every variety of appearance and circumstance, after illness, or overfatigue of the eyes or body. If you wish for an interesting account of them, you should read papers written by Buffon, Brewster, Darwin, and others, on this subject; so also, with respect to spectral illusions, you will find Dr. Hibbert on Apparitions, and Dr. Ferrier’s Essays, exceedingly instructive, and full of anecdote and interest. I now have to speak of two affections that are exceedingly troublesome, day and night blindness; the latter-viz., hemeralopia or night-blindness, comes on suddenly without any warning; the party has been well throughout the day, and as twilight approaches he finds his sight failing, and very soon he is temporarily blind. He will remain so all through the night, and in the morning, without his having pursued any treatment, his sight will return and leave him again at the approach of night. I have seen patients thus affected pre-

402

senting no peculiar appearance, excepting a rather dilated pupil. All those whom I have had to attend for this affection have been sailors or soldiers, chiefly the former; sometimes, if they were in a very light room at night, they would see, though indistinctly, some of the candles and objects, but this was not the case after a little time, and then also this dayvision became more or less indistinct, and they would have a certain degree of intolerance of light. In "The Medical Observations and Inquiries" a very interesting case is mentioned of a miller’s man, who was thus suddenly affected. He suffered for two months, and during this time he had regularly at night a slight pain over his eyes and a noise in his head, but he was quite well again in the morning; at the end of two months the blindness did not come on so regularly every night, and he recovered his sight entirely. The conclusion of the case might, however,be mentioned-viz.,that he was taking bark, and diarrhoea came on; he became delirious and deaf, and he sank. This disease has been epidemic amongst soldiers at different times. In the eighth volume of the Dublin Journal of Medical and Chemical Science there is an account of an attack of this nature in a Prussian regiment; 128 soldiers suffered. They were accused of malingering, but this was soon discovered to be an incorrect suspicion. The sentinels could not find their muskets if they had laid them down for an instant; they missed their sentry-boxes; they tumbled against each other; not one was ill in any other way, neither

We sometimes meet with an horizontal, as well as a perpendicular hemiopia. I have seen a few such cases, and all recovered under a careful treatment. Some required depletion ; others would not have borne it. In Chambers’ Edinburgh Journal there is an account, by one Jacques Balmot, of the effects produced on the eyes by the glare of the snow, when he and Dr. Paccord were ascending Mont Blanc. They had not the green veils on them which He states, that when he arrived at the are recommended. grand plateau he was so dazzled that he was nearly blind, and whichever way he looked he only saw big drops of blood. He sat down, and closed his eyes for half an hour, and was then able to go on. They passed the night in the snow. On the following morning Dr. Paccord exclaimed, " I hear the birds singing, and it is quite dark," but his eyes were open, and he was blind for the time, and only recovered after careful management for a considerable period. Mr. Lawrence also relates a case of permanent injury to the eye, from the party having been out at night, shooting, when the ground was covered with snow. Mr. White Cooper has also described the precautions adopted in some countries against snow-blindness. The Tartars and Persians wear over their eyes a veil of black horsehair net-work, to protect them against the snow; thegreenlander and Esquimaux wear snow spectacles, very curiously made. Mr. White Cooper has described them as being made of smooth wood, deeply excavated at the posterior, to allow of free motion of the lids; a notch is cut below, for the escape of the tears; the upper margin of the front surface is more prominent than the under, so that it should shade the eye; the inner surface is blackened with soot, in order to absorb some of the light. The openings for vision are horizontal and narrow slits; one is placed before each eye, and the lids are nearly closed; thus they are not only protected from the snow, but they can see distant objects more distinctly. In a memoir of General Miller, in the Edinburgh Philoso7eical Transactions, there is an account of a disease called ° Norumpi" by the Peruvians, which seized nearly the whole division of Cordova, from Cazes to Puno. There had been a heavy fall ef snow, and the effect of the reflexion of the sun from the snow brought on them the attack of this disease, which blinds persons, and causes excruciating pain. It is described as giving rise to a pimple, which forms on the eye. ball, and causes severe itching and pricking pain. The smallest degree of light, under this attack, is said to be insupportable, and therefore the poor sufferers cannot open their eyes for an instant. It is the custom to apply a poultice of snow, which affords only a temporary relief. Almost the whole of this division are said to have been, on this occasion, thus attacked at once. The guide went on far assistance, and brought numerous Indians, who then led the blinded soldiers onwards to a neighbouring village. Many had strayed away and were lost. The guides escaped by taking precautions against this exposure. Neutral-tint glasses are preferable to any others for the defending delicate eyes against an excess of light of any kind; for, as Mr. White Cooper has remarked, in his excellent little book, from which Ihave, this evening, taken several facts, it is well known that if a person’s eye has been subjected to any particular coloured light, and he subsequently looks upon an object of a white colour, he will at first form a wrong judgment as to the colour, and he will not call the object white, neither will he suppose it to be the exact colour which he had previously looked at, but will conceive it to be of another tint, which in optics is termed the complementary colour. I have marked on the diagram-board the colours, and their complementary

did their eyes present any unusual appearance; they comof having a film over their eyes. On investigation, this attack was ascribed to the heat of that summer; to excessive fatigue in ascending great heights, whereas they were natives of a low and flat country; to their frequent parades, and their dark rooms, which circumstance was supposed to have rendered their eyes more sensitive. They were removed to some more airy quarter, and with the most simple treatment they all recovered in the course of a few weeks. You may also read in the third volume of the Medico-Chirurgical Transactions an interesting report and paper by Mr. Bainfield on this subject. He states that under proper treatment they will always recover, and that soon. He found blisters particularly advantageous, in addition to low diet and aperient medicines, and the use of shades. We must conclude that it is dependent on some state of the retina under which the eyee becomes insensible to light of a moderate intensity. Cases of congenital night-blindness have been reported. I mentioned that it is most frequently seen in sailors, and it has been thought that the very fact of residing in a ship conduces to this disease. Scurvy very often accompanies iritis, and this should be treated first. The nyctalopia, or day-blindness, is very uncommon, and I have never seen a pure case of such affection; but such cases have been recorded, and accounts of such epidemics are in print. Baron Larrey used to relate a case, but this was the result of a prisoner having been for thirty-three years confined to a dungeon, and he could not bear the light of day when he was released. The late Dr. Wollaston wrote a paper on a peculiar affection from which he suffered-viz., hemiopia. You will find the paper in the Philosophical Transactions for 1824, styled, " On Semi-Decussation of the Optic Nerves." He had suffered twice from such an attack; for instance, he would only see half of a word. Thus, in attempting to read the word Johnson, he would have a blank presented to his vision over the first half, and he would only see the syllable son. He would see only the half of any object that he looked at, and the loss of sight was always towards his left side. This condition only lasted with him about fifteen minutes, and the vision gradually returned from the perfect side towards the imperfect, that is, to the left side. The attack had come on suddenly and after great fatigue, and he therefore soon forgot it; but about twenty years after this, the first attack, he suffered from a similar affection, with the exception that the defect was then to his right side: it lasted about twenty minutes, and then as suddenly left him by his being much excited by some agreeable news. I have not time to enter any farther into his interesting speculations on this subject; I must refer you to the paper itself. He died a few years after he had written it, and there was much disease found in the brain. The optic thalamus of the right side was large, and its structure altered; also the corpus striatum was much diseased. I have met with a few cases of hemiopia in private practice, and some others amongst my hospital patients. In one family I knew of three individuals who, each on different occasions, when ill, could only see the vertical half of a person’s face, ori, any other object they looked at, and as they recovered theiri’

plained

health, they got rid of this iraconveuienoe.

ones.

The hoard

was

thus ma.rkpd;—

Thus, if a person looks through blue glasses for a short time, the retina is less sensible to blue light; and therefore, when they are removed, if a piece of white paper is looked at, it will appear orange-red, because the observer sees only that colour which arises from the combination of all the rays in the white light which it reflects, with the exception of the

blue.

So also green would excite

a

violet-red spectrum.

403 the state of orange-oxide, by means of 100 parts granular starch-sugar. Thus, for every three grains of sulphate so changed, ten grains of sugar may be estimated to

Thus, then, any cause which would diminish the sensitiveness of the retina., as any particular colour would, should be avoided. The neutral-tint glasses, being of no definite colour, seem to defend the eye from all colours equally, and produce, under sunshine, the effect of a cloudy day. Spectacles are much better than reading-glasses, as they are fixed more

gether into of

exist in diabetic urine." The directions left us by Dr. Prout* for the application of Trommer’s test are very brief: " A small quantity of a solusteadily on the head, and also, as they ought to be made very tion of sulphate of copper, just sufficient to tinge the urine carefully to suit the person for whom they are intended, so blue, is to be added to the suspected urine in a test-tube. that the pupils should be opposite the centre of the glasses. Liquor potassce is then to be added in excess, till the urinè In ordering glasses for persons on whom we have operated becomes clear. Apply heat to boiling, when a deposit of red for cataract, we generally direct that two pairs should be oxide of copper will be precipitated, if sugar be present." The observations of Dr. Golding Birdt on the copper-test made, of different foci-of 2! inch focus for reading, and of 4tinch focus for walking out with, and observing distant are to the following effect:" Add to the suspected urine, in a large test-tube, just enough objects; but different patients will require a variety in this respect. Occasionally some cataract patients are able to of a solution of sulphate of copper to communicate a faint blue tint. A slight deposit of phosphate of copper generally falls. resume their usual avocations, after such operations, without using the glasses; and in some cases persons have gradually Liquor potassae must then be added in great excess; a precibeen able to discontinue the use of cataract-glasses, who had pitate of hydrated oxide of copper first falls, which redissolves used them for some time. The late Sir W. Adams related in the excess of alkali, if sugar be present, forming a blue soluthe case of a postilion, who wore the usual glasses for some tion, like ammoniuret of copper. On gently heating the mixtime after an operation for cataract; but finding that his ture to ebullition, a deposit of red suboxide falls, if sugar be employers distrusted his sight on that account, he gradually present. " Several objections have been made to this test, on the left them off, and eventually did not feel the want of them. But my time has now fully expired; and I must refer you, ground that mere uric acid is sufficient to reduce the copper, for further information on these subjects, to the works I and thus introduce a serious source of fallacy. I confess that have so often named, and from which I have derived much I have never met with any variety of urine which completely of the information and many of the facts I give you in these produced the above-described phenomena with the test, unless lectures. sugar existed. I believe the solubility of the precipitate first produced by liquor potassae in an excess of the precipitant, and its depositing a ders3 red cupreous precipitate by heat, to ON CERTAIN IMPORTANT POINTS IN THE be quite characteristic of sugar. This dense, red deposit is CHEMISTRY & PATHOLOGY OF THE URINE. very different from the light orange-coloured, flocculent clouds, which slowly subside when non-saccharine urine is BY DR. HASSALL.

I.

ILLUSTRATED

BY

NUMEROUS

ENGRAVINGS.

employed."

Dr. Bence Jonest makes the following observations in refeto this test :"To a drachm of suspected urine add two or three drops of OBSERVATIONS ON THE PRINCIPAL TESTS EMPLOYED IN THE a saturated solution of sulphate of copper, and then two DETECTION OF SUGAR IN THE URINE. drachms of caustic potash; the hydrated oxide of copper, which first is precipitated, re-dissolves; if sugar or many other The Copper, or Trommer’s Test. organic substances are present, becoming of an intense blue; THE copper-test was originally proposed by Trommer, in an and when heat is applied, if grape-sugar be present, the oxide the communication on criteria of important distinguishing of copper is rapidly reduced, and reddish-yellow suboxide of gum, dextrine, grape, and cane-sugar. is precipitated. Trommer employs this test in the following manner: he first copper " The reduction of the oxide of copper is effected by the renders the solutions to be tested alkaline, adds sulphate of carbon of the sugar. copper, and then either applies heat to the mixture, or else "If cane-sugar instead of grape-sugar be used for this exsets it aside in the cold for some hours. the rapid reduction of the oxide to the suboxide " If solution of grape-sugar," says Trommer, " and potash periment, will not take place; the bright blue solution will be formed, the be treated with a solution of sulphate of copper, till sepa- but the test must be continued to effect the reduction; rated hydrate is re-dissolved, a precipitate of red oxide will uric acid and albumenlong will also effect a slow reduction of the soon take place, at common temperatures; but it immediately oxide of copper. You will from this see that it is the rapidity forms if the mixture is heated. A liquid containing the with which the is decomposed that constitutes the 1/100000th of grape-sugar-even one-millionth part-gives a test; and hencegrape-sugar it has led, and may lead again, to many misperceptible tinge of orange, if the light is permitted to fall takes. It is always well to repeat the experiment, if it be an upon it."* unsuccessful with more or less sulphate of copper than Dr. Ure, in his " Recent Improvements in Arts, Manufac- was used in test,first the experiment. If very little sugar is pretures, and Mines," offers some comments upon Trommer’s sent, too much sulphate of copper hinders the reaction from and relates of the results further Memoir, experiments. clearly seen; if very much sugar is present, the reaction "Idissolve," writes that analyst, " a weighed portion of sul- being will come out more distinctly by adding more sulphate of phate of copper in a measured quantity of water, and make copper." the solution faintly alkaline, as tested with turmeric-paper, The above quotations contain the chief facts hitherto made by the addition of potash-lye, in the cold; for if the mixture known in reference to Trommer’s test. be hot, a portion of the disengaged green hydrate of copper It will be observed that Trommer first makes the solution is converted into black oxide. This mixture, being always to be tested alkaline, and that Dr. Ure employs an alkabefore the forms agitated applying it, test-liquor." line test liquid-precautions not adopted, so far as can be And further on, in applying the researches of Trommer and from the descriptions, by Drs. Golding Bird and himself to diabetic urine, Dr. Ure writes: "This (the urine) gathered Bence Jones. should first be boiled briskly, to decompose the urea, and to I refer to this particularly, because, as will presently dissipate its elements in the form of ammonia, as well as to appear, it is one ofpoint importance. concentrate the saccharine matter, whereby the test becomes My first endeavour was to ascertain the smallest quantity of more efficacious. Then add to the boiling urine, in a few grape-sugar which can be readily detected in distilled water; the known at a a cupreous mixture, containing time, drops for this I experimented with solutions of different quantity of sulphate of copper, till the whole assumes a strengths,purpose and I found that the 10,000th of a grain of sugar to greenish tint, and continue the heat until the colour becomes the ounce of water may be discovered with facility, and cergreen, it is a proof that more bright-orange. Should it remain tainly by means of the copper test; very much smaller quanhydrate of copper has been introduced than has been equiva- tities even be not with quite of lent to the decomposing power of the starch-sugar. I have the samesugar may a carefuldetected, although of the proportions of readiness, adjustment found that one grain of sulphate of copper in solution, super- the alkali and sulphate of copper being necessary; but for all saturated very slightly with potash, is decomposed with the it is more than sufficient to carry the test practical purposes about three production of orange protoxide, by grains of to the extent of the 10,000th of a grain. potato-sugar; or, more exactly, thirty parts of the said sulThe copper test is therefore evidently one of great nicety phate, in the state of an alkaline hydrate of copper, pass alto- and power. * Annalen der Chemie und Pharmacie, vol. xxxix. Loc. cit., p. 564. &Dag er; Loc. cit., p. 113. &dag er; Loc. cit., p. 291. (Continued from p. 270.)

rence