3DR. D. J. LEECH ON THE NITRITES AND ALLIED COMPOUNDS.

with the " arthropathic muscular wasting. " But of all thisthere was no trace before the influenza. In such cases,besides the pain that we must refer to the fibrous tissues,there is special pain along the nerves, suggesting that asecondary neuritis might have occurred and induced thesecondary pains of a neuralgic character that are its frequentsequel. In other cases such nerve pains preponderate overthe symptoms of an affection of the fibrous tissues, and thepain may quickly assume a more typical neuralgic character,occurring in paroxysms and sometimes changing its seat. Itis then a matter of doubt how far the original affection was

Ian intense neuralgia or an actual neuritis of limited seat, (but in most of the cases that come into this group a limitedprimary neuritis is the more probable. A hard-workinglawyer of sixty-three, who had been liable to neuralgia, hadan attack of influenza in which the pain in the back was verysevere. When the acute disease was over this pain did not ceasebut became fixed about the lower dorsal and lumbar spine and

. gradually extended obliquely forwards and downwards on eachside of the abdomen, apparently in the course of the lowerdorsal and lumbar nerves. At first it was spontaneous andmore or less paroxysmal, but when I saw him six monthsafter the onset it was gradually subsiding, had ceased to bespontaneous and was felt only on movement. Again, a Iyoung and active medical practitioner had an attack of in-fluenza which was not severe-not severe enough, indeed, tocompel him to use the necessary caution. He yielded to theurgent claims of others, which have made the disease so fatalin our profession, and went about before he was well ; arelapse compelled him again to take to bed, and there he hadto stay for three months. In a few days severe pain came onin the right side of the chest, about the ninth or tenth inter-costal nerves. It was so intense that for weeks he could notlie down in bed, and the inhibition of respiration causedconstant gasping dyspnoea. Not the slightest trace of intra-thoracic mischief could be discovered, but the pain went on,and only ceased occasionally on the right side, when it wasfelt, in less degree, in the corresponding part of the left side.It disabled him for work for several months, and even then,although slighter, it still occurred and was felt from time totime. Even three years after the primary illness it troubledhim, being chiefly excited by exertion and sometimes lastingfor a week. The pain was at first, and indeed always,accompanied with tenderness and he had occasional pains inthe lower part of the spine.The most common form of nerve-pain after influenza is,

however, primary neuralgia, in which there is no suspicionof neuritis, in spite of the fact that this also may be accom-panied by some rheumatic pain. On the same page of mycase book on which the last is recorded I find the notes ofanother which illustrates the manner in which neuralgicpains may seem to grow out of the severe headache of influ-enza. In this patient, a man of fifty-two, the pain persistediri more limited position, occupying the frontal region andbecoming distinctly paroxysmal. It continued and hadbecome almost constant when I saw him four monthsafter the influenza ; sharp pain started from the bridgeof the nose and passed to each temple, and whensevere would extend in less degree to the back of thehead. Exacerbations, lasting two or three days, oftenoccurred, and during them slight pain was felt in the eyesand their use induced a feeling of giddiness. In this caseno antecedent predisposition could be traced. The mostcommon seat for post-influenzal neuralgia is in the region ofthe head, as might be expected from the pain of the primarydisease. The most frequent varieties are : supra-orbital,supra-maxillary, ophthalmic, cervico-occipital and cervico-brachial ; but it is not uncommon in the arm and sideof the chest, and in certain cases it is apparently deter-mined by some local influence. Thus a lady had an

innocent tumour in the left breast and soon afterwardsendured an attack of influenza, in which the pain firstfixed itself in the breast and then extended to theleft arm, becoming there particularly severe. The tumour ofthe breast was removed, but the pain in the arm continuedup to the time I saw her, a year after the influenza, and thenextended down the inner side of the arm and forearm to theinner or sometimes to the outer side of the hand. Whensevere it radiated to the scapula, and sometimes was felt inslight degree in the other arm. Except for a history oflumbago there was n indication of a diathetic predisposi-tion. It is an instance of the extremely prolonged durationof some of the cases of post-influenzal neuralgia.

(To be coKch((M.)

The Croonian LecturesON THE

PHARMACOLOGICAL ACTION AND THERA-PEUTIC USES OF THE NITRITES

AND ALLIED COMPOUNDS.Delivered at the Royal College of Physicians of London

on June 22nd,

BY D. J. LEECH, M.D., F.R.C.P. LOND.,SENIOR PHYSICIAN TO THE MANCHESTER ROYAL INFIRMARY AND

PROFESSOR OF MATERIA MEDICA AND THERAPEUTICS ATTHE VICTORIA UNIVERSITY, MANCHESTER.

LECTURE II.—PHARMACOLOGY OF THE NITRITES.

INFLUENCE OF NITRITES ON THE NERVOUS SYSTEM.

MR. PRESIDENT AND GENTLEMEN,-The nitrites depress thefunctions of the nerve centres and nerves, but not to the extentwhich might be expected from their influence on the muscles,vessels and heart. When given in toxic doses they cause in bothcold-blooded and warm-blooded animals heaviness and apathy.In man, too, cerebral depression has been seen after to:-icdoses. Inhalation of the vapours of nitrous ether has beenfollowed by stupor, and after nitrite of amyl in large quantLties loss of consciousness has occurred. Such effects are

probably due to the direct influence of nitrites on the cere-brum. I have never seen a narcotic influence exercised bymedicinal doses of the nitrites, but drowsiness after nitro-glycerine, which acts like the nitrites, has been recorded. IThis may be the outcome of the circulatory disturbance it

causes ; certainly no narcotic effect has to be feared from theuse of nitrites. The sense of distension and throbbing in thehead, the dizziness and the headache felt by some after takingamyl, ethyl, or sodium nitrites are manifestly due to circu-latory changes ; but the prolonged headache, which does notcome on always immediately, but may last for twelve hours ormore after some nitrites have been taken, is probably not due tothe same cause. It is most frequent after amyl and isobutylcompounds. I have felt it myself after both, and also afterpropyl compounds, but not after ethyl nitrite or sodium nitrite.I am inclined to think it is caused by the alcoholic radicles,and not by the nitrite element, for other amyl, isobutyl andpropyl compounds produce the same kind of long-lasting head-ache. Convulsions in the lower animals are rare after nitrites.

They are said to have occurred in man after the injectioaof amyl nitrite.2 I once saw twitching of the eye muscles

: accompany a syncopal condition which followed on theadministration of nitrite of amyl. Dr. Brunton, too, alludes

to the occurrence of a slight convulsme attack after the samel drug. It seems likely that such attacks are connected with; syncope or slight asphyxia rather than with a direct action ofj the drug on the brain, and; considering the rarity of cerebraldisturbance after any of the nitrites and the entire absencefof the fatality when they have appeared, we may, I think,r safely conclude that, though the nitrites may cause some

unpleasant symptoms, yet their influence on the cerebrum is no bar to their use even in full medicinal doses. The func-tions of the cord as well as of the muscles are in frogs. depressed by nitrites, both its reflex and conducting power1 being diminished, the latter, according to Dr. Atkinson, muchmore slowly than the former. Dr. H. Wood says that the

t diminution of reflex activity caused by amyl nitrite is never2 preceded by functional excitement. In man other symptomsf so far predominate that even from toxic doses no distinct1 indication of an effect on the spinal cord has been noticed.1 We have no proof that the motor nerves are markedly influ-eenced by the nitrites, nor are the nerve endings especiallyaffected by them; at least, it can be shown that they arennot more powerfully depressed than are the muscles. On

f exposing a muscle to a solution of 1 in 1000 of sodium nitrite

1 Murrell: Nitroglycerine as a Remedy in Angina Pectoris, p. 17.2 Strahan: Journal of Mental Science, vol. xxx., p. 252. There is

some doubt whether these convulsions were altogether due to theinjection.

4 DR. D. J. LEECH ON THE NIFRITES AND ALLIED COMPOUNDS.

and recording the contractions produced by stimulation of the Imuscle and nerve alternately t find that the relative effect ofthe strength of stimulation is continuously maintained untilthe death of the muscle (See Fig 6 ) No evidence has beengiven that even in toxic doses sensory paralysis is produced orthat the application of sodium nitrite paralyses the sensory nerveendings.3 To determine whether it possesses any analgesic influ-ence other than that which arises from its effect on the circula-tion, I have tried it locally and generally for the relief of pain.Locally applied, I have not found it to possess the slightestsoothing influence. I have given it internally in. doses offrom three to five grains for the relief of pain in variousailments ; but save in the case of pains of an anginal character,in headache, and very rarely in neuralgia, I have never foundit to be of the slightest benefit. In all cases in which it was

given with relief there have been grounds for thinking thatthe disappearance of the pain may have been due to circu-latory changes or to suggestion. It has failed to relieve painswhere other analgesics have succeeded. A few cases are,indeed, recorded in which the local application of nitrite ofamyl and nitroglycerine is said to have removed the painof toothache and many where these drugs have relievedheadache and neuralgia ; but such ailments are so capable ofrelief by vascular alterations and mental influence that wecannot, in the absence of other indications, infer from theirrelief that amyl nitrite has a direct analgesic influence.

GENERAL INFLUENCE ON THE CIRCULATION.I have already alluded to the action of nitrites on the con-

tractile tissue of the vessel walls and on the heart muscle,but the general inauence on the circulation requires furthernotice. The most important feature of this influence is thelowering of arterial tension. Dr. Brunton4 in 1870 showedthat the lowering of tension was due to dilatation of thebloodvessels, and from the fact that this dilatation occurredeven after section of the cord he came to the conclusion that thenitrites act on the muscular walls of the arterioles, influencingthe muscle fibre directly or through the local ganglia. Thisview was controverted by Dr. Filehne5 on the ground thatsection of the sympathetic interferes with the vasculardilatation produced by the nitrite, and by Dr. Bernheim 6because after arterioles are dilated by amyl nitrite they maybe made to contract by vaso-motor stimulation. The experi-ments of Drs. Meyer and Friedreich7 supported the viewswhich Dr. Brunton bad expressed ; they found that when theeffect of nitrite of amyl is restricted to the brain it does notbring about a fa.lL of pressure. The dilatation of the vessels bynitrites when the brain and spinal cord have been destroyed,and in separated organs, which can only result from their influ-ence on the vessel walls, is of course much in favour of theview that they lower tension by their action on the peripheralvessels ; and Professor Cash8 has advanced further evidencethat the effect of nitrite in reducing tension is the result ofits action on the vessels. Like Drs. Meyer and Friedreich,he finds that nitrite of amyl produces no effect on thecirculation when its influence is restricted to the brain ; buthe has further shown that if the head of an animal be cutoff from the circulation inhalation of pure amyl nitrite causesa rapid fall of pressure, which cannot therefore be due toinfluence on the vaso-motor centre. He also points out thatafter reduction of tension by division of the splanchnicnerves the nitrites cause a further fall of pressure. Besides

reducing the tension the nitrites usually quicken the

pulse, and this quickening is generally accompanied, if thedose be small, by such an apparent increase in force as togive the impression that a stimulant effect on the heart hasbeen produced, for the pulse feels fuller and more distinct.Yet experimental evidence indicates that nitrites do not

strengthen the actual force of the heart’s beat and that theyare capable, even in comparatively small amounts, of weaken-ing the cardiac contraction.The question whether nitrites are, as Dr. Reichert strongly

maintains, real cardiac stimulants or not is an importantone, for we find nitrites recommended not only wheretension is high and relief might be expected from drugswhich lower it, but in syncope, heart failure from chloro-form, and other conditions in .which a stimulant is indi-cated rather than a tension reducer, and in which any drug

8 Journal of Anatomy and Physiology, vol. v. 4 Pfluger’s-Archiv, vol. ix. 5 Ibid., vol. viii.

6 Archiv. fur Experimentelle Pathologie und Pharmacologie, vol. v.7 Proceedings of the Royal Society, 1891.

8 Reichert (American Journal of the Medical Sciences, July, 1880,p. 168).

which greatly depresses the heart might produce seriousconsequences. It may be well if I state the main facts con-cerning the effect of nitrites on the heart which bear uponthis question. As I have shown, nitrites in the isolated frog’sheart cause acceleration of beat for a short time, though thecontractions are rendered somewhat less powerful and after-wards slower. - Dr. Atkinson employed 1 of nitrite to 10,000of blood, and, using Williams’ apparatus, noticed a risein pressure for some minutes, which he attributes to a

quickened action of the heart; it was followed by a slowfall and death in from forty to sixty minutes. With 1 in20,000 the rise due to quickened action lasted from ten tofifteen minutes. In no case has any actual increase in theforce of the heart’s contraction been observed ; but the totalwork of the heart may be augmented by the increased rapidityof beat. We may presume that a quickening of the heart’saction similar to that in frogs takes place in mammals fromthe direct action of the nitrite on the heart muscle, but here afurther quickening is produced by the paralysing influencewhich nitrite can be shown to exercise on the vaguscentre. In mammals, then, as in frogs, no evidence hasyet been obtained to show that the individual beats ofthe heart are strengthened by nitrites, although at first,acting more rapidly, it may do more work in a giventime ; but the increase in rapidity does not make up forthe weakened muscular power and dilatation of the vesselsand the tension falls. Only one observer, Dr. Reichert,9 records a slight rise in tension after the introduction of nitritesinto the circulation, and this for not more than half a minute.If, as experiments seem to show, the effect of nitrites isonly to quicken the heart’s action and not to increase theforce of its individual contractions, how are we to accountfor the markedly greater distinctness of the pulse whichis so often noted after the administration of nitrites, andfor the increased height in the upstroke - the so-called"percussion wave" -of the tracing which is almost in-

variably seen after small doses of nitrites ? Probably twocauses contribute to this : (1) Owing to the dilatation ofthe arterioles the collapse of the artery is more completeafter a dose of nitrite than before it, and the differencebetween systole and diastole of the artery is more markedboth to the finger and in the tracing; (2) the radial arteryundergoes greater dilatation owing to the relaxation of itswalls under nitrite influence. The pulse, therefore, becomeslarger during systole, and, the difference between the calibreof the artery in systole and diastole being augmented, itis felt to be more distinct and more full.

Mr. Pickering Pick many years ago suggested that arterialdilatation might in a reflex manner give rise to increased forceof heart-beat. If this were the case, we ought to find in themanometrical tracing taken from the carotid of a dog underthe influence of a small dose of sodium nitrite that the fallin tension is accompanied by an increase in the excursions,corresponding to the individual heart-beat ; but this is notso, and until we have more evidence we must conclude that,though the heart may do more work in a given time, theforce of the cardiac contractions is not increased by nitrites.Although we have no proof that nitrites will increase theforce of the heart’s beat, we have experimental evidencethat they are competent to weaken it, and faintness is

occasionally complained of after their administration. Theinhalation of amyl nitrite and large doses of sodiumand ethyl nitrite are capable of producing it. On oneoccasion I myself suffered from a very marked syncopalattack after taking a large dose of ethyl nitrite. Whilstmy tracing was being taken I suddenly felt faint, the heartbeat became slow and the excursion smaller; then a pro-longed intermission occurred and faintness compelled meto lie down ; the slow beat continued for some minutes afterthe faint feeling had disappeared. I may mention, in passing,a curious result which followed from publishing in a medicaljournal a warning with regard to this effect without statingthat I was myself the subject of the experiment. A yearor two after the record appeared an anonymous novel waspublished, purporting to show that in consequence of vivi-section being allowed hospital physicians and surgeons ex-perimented upon their patients in a horrible manner ; andsubsequently an appendix called " Dying Scientifically was

issued, giving the sources from which had been culledtheheart-rending illustrations of the barbarity of hospital physiciansand surgeons with which the novel was filled. Lightingaccidentally upon this book some time afterwards, I was

9 Ibid., p. 170.

5DR. D. J. LEECH ON THE NITRITES AND ALLIED COMPOUNDS.

amused to find that the experiment upon myself was one of thebases of the attack made on hospital physicians and surgeons.Who, it was asked, were the patients on whom such experi-ments were tried ; and where were they found if not in the...... Infirmary 7 ,And so the trial of the drug on myself wasput down as proof of the dangerous experiments made byhospital practitioners upon their patients. This is but another

example of the way in which anti-vivisectionist writers getat the "facts " wherewith they try to influence the publicmind. I have never myself seen any tendency to syncopeafter 3-grain doses of sodium nitrite, although I have giventhis amount extensively. It has been known to occur afterthis and larger doses.

In deciding whether the nitrites can play the partof cardiac stimulants, it is well to bear in mind the re-semblance and differences between their action on thecirculation and that of alcohol. Both dilate the vessels.Alcohol, like the nitrites, increases the frequency and-tothe finger-the force of the pulse ; but, though experi-menters are not agreed as to whether it increases eitherthe power of the heart’s contraction or the amountof work it does, all hold that alcohol in large amountsdecreases the heart’s power. In these points there is con-siderable likeness between the action of alcohol and thatof the nitrites. The difference between the two seems tobe that the nitrites are far more rapid and seemingly moreevanescent in their action. They quicken the beats more

markedly and dilate the vessels more quickly and com-pletely. They far more readily depress the action of theheart. On the whole, it seems to me that we must accord tonitrites in small doses a certain degree of that kind of stimu-lating power which we attribute to alcohol, but it is exercisedmuch more quickly, passes away more rapidly, and is farmore readily followed by decreased cardiac power than isalcohol.There are several points of considerable practical interest

to be noted with regard to the effects of nitrites on thetension and the rate of the pulse and on the regularity ofthe heart beat. The influence of nitrites in the relief of diseaseis closely associated with, if not dependent on, its tension-reducing powers. It is important, therefore, that we shouldknow how quickly the effects of the various nitrites on tensionare produced and how long we may expect them to last.Changes in arterial tension are not often indicated by sub-jective phenomena, and their extent and duration can only bemeasured by the sphygmograph. With this instrument Ihave tried, by means of tracings taken frequently, to estimatethe time at which it reaches its lowest point and its duration.The influence of amyl nitrite on the pulse commences a fewseconds after inhalation. (Fig. 17.) The tension is reducedto its lowest point in from forty to sixty seconds and remainsextremely low for thirty or forty seconds, the pulse wavesbeing reduced in size and sometimes irregular. Then it rises

FIG. 17.

Effect of amyl nitrite when inhaled and of amyl nitrite and nitratewhen taken internally.

again, occasionally suddenly, and in from a minute and a halfto two minutes the pulse is only a little lower in tension thanit was befoie the inhalation. This slight lowering may con-tinue for several minutes. Isobutyl and isopropyl nitriteswhen inhaled almost act like amyl nitrite. Sir B. W. Richard-son, to whom we are so much indebted for knowledge con-

cerning amyl nitrite, has drawn attention to the fact thatwhen it is taken internally its effects are much slighter.though more prolonged, than when inhaled. Instead ofthe tension falling at once and recovering in two minutesit falls gradually for usually twenty to twenty-five minute?,remains low a short time, and then rises to its normalheight an hour to an hour and a half after the dose hasbeen taken. Because amyl nitrite is such a powerfulagent when inhaled one drop is regarded as the proper dose,but this is a mistake; from three to five minims may be

required’ to produce about the same effect as that whichfollows two grains of sodium nitrite. A small dose ofsodium nitrite (two grains) distinctly affects the pulsein two or three minutes ; the point of lowest tension is

usually reached in from eight to forty minutes, ard dis-tinct influence on tension ceased in from one to three hours.

Ethyl nitrite has much the same effect, and on the wholelasts as short a time. I shall not here allude to the action ofother metallic nitrites, since, with the exception perhaps ofthe strontium salt, they are unlikely to prove useful remedialagents. The combination of cobalt with potassium I once

thought might prove useful, but its efftcts are unreliable,because its decomposition is so greatly modified by thecondition of the stomach. The table gives a general ideaof the influence on pulse tension and frequency of the twonitrites and nitroglycerine in small doses. Four observa-tions on each drug have been selected from a large numberto illustrate the variations which occur in their action.

I have used the term ’’ duration of action" to signify the periodbetween the time at which the drug is taken and the time ,twhich the tracing first becomes normal, but this may not be thereal limit of the action of nitrites on the vascular system. It is

quite possible that some vessels, as for example those of thebrain, may continue dilated after others have assumed theirnormal condition. After the tension becomes normal itsometimes falls again slightly, and I have noticed smalloscillations in tension for a short time. How long they lastI do not know, for they merge gradually into those minordifferences which are observed in normal pulse tracings. For

practical purposes we may look on the influence of the nitriteas ended when the pulse first reaches its normal tension. It has been suggested that after the lowering of tension bythe nitrites reaction may occur and the tension mayrise above the normal. Though I have looked for suchrise I have found no distinct evidence of it. Many con-ditions influence the amount of fall in tension andits duration. In persons with high tension pulses thefall is less in degree and duration than in those with a circa-lation of low tension ; in those who constantly take nitritesthe influence of the drug on the circulation, though not lost, isdistinctly lessened. Though persons vary very much in sliseep-tibility, I have never seen anyone entirely uuaffected by sucha dose as two grains of sodium nitrite or the inhalations ofamyl nitrite, but when the tension is very high, and some-times during attacks of dyspnoea, the effect may be very slight.The administration of from ten to fifteen grains of bicarbonateof soda with the nitrite delays the appearance of decidedlower tension for a few minutes (from six to ten) and seems tolengthen somewhat the time during which the drug acts.A point of great interest in the action of the nitrites

6 DR. C. BELL TAYLOR ON DISEASES OF THE EYE.

is the minuteness of the amount which will affect thecirculation ; one-sixteenth of a grain of nitrite of sodium

produces a distinct effect on the pulse in most persons.The effect on the circulation does not increase so much aswe should expect with the size of the dose. Two grains ofsodium nitrite of course lower the tension more and for alonger time than one-sixteenth of a grain, yet the influence isnot proportionate to the difference in dose. From four to sixgrains, again, lower the tension a little more, and sometimesfor half an hour longer, than two grains, but here again theeffects are not in proportion to the increased size of dose andthey commence no earlier. The cause of the differencebetween the action of any nitrite when inhaled and whentaken by the mouth probably depends upon the fact thatwhen inhaled the whole nitrite of amyl molecule comes at oncein contact with the vessel walls in the systemic system. Nowamyl in very small doses dilates the vessels as a nitrite does,and quite possibly the amyl molecule accentuates the action ofthe nitrite molecule. Professor Cash finds that the compositionand constitution of the fatty molecules have a distinct effecton the tension-reducing power of the corresponding nitrite.The quickening of the pulse after amyl nitrite is verymarked, arise from twenty to thirty beats being common. Afternitrite of sodium and nitrite of ethyl in small doses there isusually slight quickening, but it is not always present. Itis very difficult, however, to estimate the influence of a drugon the rapidity of the pulse, since the frequency of theheart’s action is so easily influenced by slight circumstances.A decreased frequency of the pulse is sometimes seen afternitrites, but this, with small doses at least, is never consider-able. After poisonous doses marked slowing of the hearthas been in some cases noted. This may be due to thedirect influence of the drug upon the heart. It will beremembered that nitrites render the beat of the isolatedheart slow after first quickening it. Irregularity of theheart’s action has been observed after the administrationof nitrites, and in a few cases extreme irregularity has been reported after large doses of sodium nitrite andinhalation of amyl nitrite. Using small doses of thesodium compound, I have never seen any marked irregu-larity result. In two or three instances out of forty or fiftyin which the pulse has been watched carefully for manyhours after sodium or ethyl nitrite slight intermission andirregularity have occurred, which had not been recordedbefore the nitrite was given. Slight irregularity of the pulseis common after the inhalation of amyl, isobutyl and propyl

nitrite. On the other hand, I have met with at least fourcases in which an irregular action, fairly marked before theadministration of nitrites, became distinctly less or dis-appeared entirely when nitrites were given. I have neverseen it seriously increased and I am quite sure that the irregu-larity of the pulse is no bar to the administration of nitriteswhen for other reasons they are called for. Amyl nitritemarkedly dilates the vessels of the face, neck and upper partof the chest, but evidence of its ciitaneoiis influence is notusually seen in other parts of the body. Flushing of the faceis not common after either sodium or ethyl nitrite, yet insome cases it occurs to a slight extent, and in one exceptionalcase I have known a slight diffused redness over the body aswell as the face follow three grains of sodium nitrite.

(To be continued.)

Clinical LecturesON

DISEASES OF THE EYE,BY C.BELL TAYLOR, F.R.C.S.EDIN., M.D. EDIN.,

SURGEON TO THE NOTTINGHAM AND MIDLAND EYE INFIRMARY.

LECTURE IX.

Cataract Extraction.

GENTLEMEN,-When Professor Waldau, the late von

Graefe’s assistant, proposed to excise a small portion of theiris and to scoop out cataracts with a spoon he did so because,although at that time suppuration of the eyeball was by nomeans rare after cataract extraction, it was hardly ever

observed as a result of simple iridectomy. It occurred to methat a slight enlargement of Waldau’s incision would enableus to dispense with the spoon, and it was no doubt by asimilar process of reasoning that von Graefe was led to theadoption of his celebrated method of linear extraction. Von

Graefe, however, whilst dispensing with the spoon, placed hisincision much further back than Waldau’s, in order, as hesaid, that it might coincide with a meridian of the globe ;and as it was obviously impossible to make such a woundeither with the broad keratome used in Waldau’s operation(Fig. 1) or with the equally broad cataract knife then in vogue

(Fig. 2) it became necessary to invent the long, narrow-

bladed instrument (Fig. 3), which is known as von Graefe’s,and which has since proved to be such a valuable addition tothe armamentarium of the ophthalmic surgeon. The advan-

tages claimed for von Graefe’s operation are the following: Thesclerotic, which alone is incised, is much less likely to suppu-rate than the cornea ; the elasticity of the tissues in thissituation and the linear character of the wound render sepa-ration of its edges almost impossible ; whilst the conjunctivalflap, which becomes at once agglutinated to the sclera, is apotent safeguard against microbial infection. On the otherhand a large iridectomy is necessary with this form of incision.The close approximation of the edges of the wound-whilstensuring quick healing-renders the delivery of the lens some-what difficult ; haemorrhage often’ complicates the extraction,the vitreous is prone to protrude, and iritis, irido-cyclitis,and sympathetic ophthalmia are more apt to occur with thisthan with almost any other cataract operation. Clearly thedrawbacks exceed the advantages ; hence those who adopted,or who were supposed to have adopted, von Graefe’s opera-tion invariably modified it, so that it is now commonly saidthat " nothing remains of the original method but the knife."

"

1 Manolescu, Knapp and others : Transactions of the HeidelbergCongress, 1886, p. 164.