4442.

OCTOBER 17, 1908.

An AddressON

A JUST PERSPECTIVE IN MEDICINE.Delivered before the Guy’s Hospital Physical Society

on Oct. 8th, 1908,

BY SIR RICHARD DOUGLAS POWELL, BART.,K.C.V.O., M.D. LOND.,

PRESIDENT OF THE ROYAL COLLEGE OF PHYSICIANS OF LONDON;PHYSICIAN-IN-ORDINARY TO THE KING; EMERITUS LECTURER

ON MEDICINE AT MIDDLESEX HOSPITAL.

MR. PRESIDENT AND GENTLEMEN,-It is now some 14

years since, at Torquay,l I dealt with the subject of mypresent discourse, and when your President and Council didme the honour to invite me to address you to-day it occurredto me that it might be of some interest-both to my audienceand myself-if I were to revert to the subject, seeking furtherillustrations in the light of much that has happened since inthe way of medical developments. I then defined what Imeant by a right perspective as being a perception of mattersunder immediate scrutiny or contemplation in their due pro-portion to other associated matters and thoughts within thesame field of view ; for perspective in one sense-perhapsnot the most usual one-means an appropriate relation ofparts to one another and to the whole view or subject.The gift to see things in their due relationship with other

things is possessed by but few people and it is not a littlecurious to observe how in politics, religion, science, and even

art, persons lose their sense of perspective as they becomeengrossed in the study of one special department or aspectof things. The State wisely recognises this weakness ofhuman nature even in the great, by adopting the apparentanomaly of putting men of general affairs rather than

specialists in control of departments, men of business ratherthan soldiers or sailors at the head of the War Departments,a brilliant man of letters at the head of the Department forIndia, and anyone rather than a schoolmaster to superintendeducation. So in medicine or surgery it is wise that everyspecialist should have an assessor, and the force of this last

remark gathers momentum of application with the increasingnumber and profoundly increasing complexity in techniqueof the specialties in practice and research that have

developed in our great science of medicine within recenttimes.

At the time of my previous address the use of the clinicalthermometer had long been established, indeed the instru-ment had already become a part of the average householdequipment. In the eyes of the public the temperature in allactive diseases had become the objective of attack anddefence, the criterion of hope and fear ; the pulse andrespirations were registered in comparatively obscure cornersof the chart, written in small print, and one noticed a

growing disposition in students to neglect to feel the qualityof the pulse, or to note the characters of the breathing,leaving them rather for the nurse to record, and merelyglancing at them when inspecting the temperature so boldlyoutlined on the chart. How few practitioners, indeed, thereare who have acquired the art of accurately gauging thearterial resistance, cardiac power, and reserve vitality, andmuch else that may be learned of the patient by the

characters of his pulse. Like many other quotations, 11 Thehand of little employment hath the daintier sense " has nomeaning outside its context and particularly does not applyto medicine. I am glad to see a growing tendency, which Ithink we owe to the abdominal surgeons, to render in

equivalent lines temperature, pulse, and respiration. It atleast broadens the view of the case by recording the three

great indices of clinical medicine, to be analytically read andexamined in the light of experience and in perspective withall other conditions.With the importance that was attached to every movement

of the thermometer there could be little wonder thatmeasures were soon discovered-in the use of syntheticremedies-that should lower its records. Antipyrin wasone of the first of such drugs which had the brilliant and

1 A Right Perspective in Medical Thought and Practice, THE LANCET,Oct. 20th. 1894. p. 903.

obvious effect of lowering the peaks of temperature. Evenwith our imperfect insight at that time into the real meaningof fever temperatures there was still a want of perspective inour reading of and attacking such temperatures. We knewbetter, but were obsessed on the one hand by a magnifiedimportance assigned to mere temperature, and on theother by the inadequately appreciated efficacy of a

new class of remedies. It was about that time thathyperpyrexia with its fatal consequences had gainedhold upon the professional mind, and thus one wayand another practitioners got into the habit of chasingthe temperature round the dial with antipyretic remedies.I ventured, at the time I am speaking of, to point out that"recent and, as yet, not fully disclosed pathological

researches give a new interpretation to some pyrexialphenomena which the thermometer but faithfully records,and are shedding a new light upon the natural history ofpyrexial diseases. Thus the interesting stories which-some of them, perhaps, fables-come to us from our

bacteriological laboratories, of the loves and antipathies,the triumphs and disasters, in the microbe world, assume anew and strange fascination for us as we come to recogniseourselves, our blood and tissues, as forming more and morelargely their playgrounds and battlefields." The story ofmicrobic action in specific diseases has year by year grownin incident and importance and presents to us chapter uponchapter of surpassing interest.The fact was then well known that the organisms specific

to most of the acute diseases-tubercle, anthrax, pneu-monia, influenza, enteric fever, and perhaps rheumatism-germinated at or above blood heat and that their multiplica-tion was retarded or arrested, although they were not killed,at the higher degrees of fever, about and above 104° F., andit seemed to me that the tendency in practice was to pay toomuch attention to the higher excursions of the thermometerand to ignore or even to seek to bring about low ranges ordeep depressions as salutary or of negative importance. Thisview was growing upon many physicians after three or fouryears’ experience of disastrous epidemics of influenza, andDr. Hale White particularly gave the weight of his authorityin favour of the same warning. Every febrile disease has atemperature of its own. Pyrexia is, indeed, a normal re-action to toxic invasion, and a rise of temperature is a sym-ptom as proper to certain diseases as a normal temperatureis to health. Antipyretic remedies should therefore beused to moderate those degrees of temperature which aredangerous to the integrity of the nervous system, heart, andkidneys, not with the aim of giving a subnormal range to apyrexial disease.

,. -... - - -- - -

The demonstration by Cohnheim in 1867 of the importantpart taken by the leucocytes in the process of inflammation,which had, I believe, been already inferred by Addison aquarter of a century before, was a great addition to thecellular pathology of Virchow which prevailed in those days ;and, as some of you remember, Cohnheim’s views on themigrations of leucocytes caused no little commotion amongstthose who had abandoned the antecedent exudation theoriesin favour of cell multiplication in the parenchyma or

alveolar or intercellular tissues in inflammation and in

growths. The brilliant discovery many years later byMetchnikoff of the phagocytic function of the leucocytesgave a new significance to their migration towards centresof irritation which Cohnheim had demonstrated. More

recently still the equally brilliant work of Sir Almroth Wrighthas disclosed certain opsonic powers in the blood serum whichaid and encourage phagocytic action. Even to-day, however,if we are asked why a toxin produces fever, we can onlyanswer because it is a poison acting upon the thermiccentres through certain channels, and if the question is putwhy certain leucocytes attack bacteria we can only say theyare living beings and" ’tis their vocation " to go for theforeigners more or less like trout for the May fly I The factthat leucocytes press towards local centres of inflammationwhich are invaded by bacteria is a part, the very first line,of the old story "ubi irritatio ibi imxus, with all theadditional meaning which modern pathology reads into it.And when finally we inquire of the blood in what con-

sists its opsonic power, we are more than ever nonplussedand call to mind the witty simile used by a certain learnedbody which in discussing with Dr. Martinus Scriblerus thenature of self-consciousness compared it to the "meat

roasting quality of a jack," which resides neither in the, Q

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fly, nor the weight, nor the wheel, but is the result of thewhole composition. I ventured to ask in reviewing the firstdiscussion on tuberculin treatment as regulated by observa-tion of the opsonic index, whether any chemical researcheshad been undertaken to ascertain the nature (chemical,I presumed) of this opsonic quality in the serum. Idid not meet with an encouraging response, and I amnot aware that any special inquiry has been made intothe matter. Is it a property of the serum or a secretionadded to it from the cellular elements of the blood ? Thelatter seems the more probable-viz., to continue our

simile, that the "meat-roasting quality " adapted for eachparticular bacillus is yielded by the vital action of the

phagocytes, that these little spitfires do, indeed, secrete

something into the serum that obsesses their prey andrenders it more amenable to absorption and digestion.Shattock and Dudgeon 3 apparently assume opsonin to be a Iparticulate substance capable of adhesion to and removalfrom the serum by inanimate matter such as melanin. Butalthough speculative, the view I have suggested seems to me ’,most in accordance with the trend of opinion, to which we ’’

are drawn by the work of Wright and the side-lights castupon it by the researches of Strangways, Shattock, and ’many others. I

Natural and acquired immunity to specific diseases has forages been a matter of knowledge from observation. The greatJenner at the end of the eighteenth century was the firstto give it any specific meaning and to utilise it to anyspecific purpose, although it was practically accepted in thetime of Lady Mary Wortley Montagu 80 years earlier, wheninoculation was introduced as a preventive of small-pox,and met, in the middle of the century, with the approval ofthe Royal College of Physicians. But Koch and Wrighthave within very recent years given considerable precisionand practical direction to measures for securing immunity.For, all fallacies to the contrary notwithstanding, as thelawyers say, we have learned from them that minute anddefinite doses of toxins, such as are attached to the bodiesof dead and sterilised bacilli, cause a reaction in the bloodof an antagonistic kind, which results in the raising of itsopsonic qualities with regard to the particular bacillusconcerned; and the fact that definite doses of a given specificpoison cause a reactive immunity-a phagocytic antagonismto the organisms that produce the poison-has a very wideapplication in clinical medicine and gives a clearer insightwith regard to mlich that has already become a part of ourpathological and therapeutical experience. Thus we see moreclearly why the routine sanatorium treatment of phthisicalpatients by exercise and rest, as regulated by the indicationsof the temperature chart, is sound practice. For the pastthree years Dr. M. S. Paterson at the Frimley branch of theBrompton Hospital has adopted more thoroughly organisedand closely supervised and graduated labour exercises, atfirst regulated by the readings of the clinical thermometeralone, but in the past year supplemented by careful opsonictests, which, under the direction of Dr. A. C. Inman, arefound closely to correspond with the thermometric indications.Similarly beneficial results have been observed in arthritisand other bacterial lesions from the alternating conditions ofanaemia and congestion locally effected by massage and themethods of Bier, and it has long been known both to

physicians and surgeons that the opening up of serous

cavities with free drainage will sometimes suffice to cure apleurisy or a peritonitis which is demonstrably of tubercu-lous nature. Wright and his pupils explain these clinicalobservations by showing that by exercises or mechanicalmeans such a moderated degree of afflux of blood can besecured to a local or more or less quiescent tuberculous orother bacterial lesion, as will cause a discharge of toxin fromit, and so produce a reactive upraising of the opsonic powerof the blood serum and secure more effective phagocyticaction. At the same time it must not be forgotten that alarger number of leucocytes are brought within the diseaseareas. These clinical methods of producing immunity aremore nearly on all fours with the idea of vaccination, so faras the original idea is acceptable, than the artificial use aloneof the sterilised toxins.

It is absolutely essential, on economic grounds as wellas’ on those of clinical convenience, that a workableclinical index be fd’und to guide the use of vaccines, whether2 Transactions of the Royal Medical and Chirurgical Society,

vol. lxxxix., p. 117.3 Proceedings of the Royal Society, B., vol. lxxx., 1908, p. 169.

given artificially or absorbed automatically under exerciseconditions, in the treatment of tuberculous and otherbacterial diseases of any duration, before such methods oftreatment can become largely available for private patientsfor whom costly and expert opsonic observations are notavailable. Laboratory work must be brought into line withclinical observation in this, as in many other respects, inorder that its results may attain full value. An importantbeginning has already been made in this direction by mycolleague Dr. A. Latham who, in association with Dr. H. R. D,Spitta of St. George’s Hospital and Dr. Inman of BromptonHospital, has contributed a valuable and suggestive paper tothe Royal Society of Medicine, which treats of the relation ofthe opsonic indices to temperature and discusses the value ofthe temperature curve as a guide in tuberculin treatment.The clinical observations of Dr. Latham and the opsonic

examinations of Dr. Inman and Dr. Spitta strongly supportthe view that with an initial opsonic observation, and perhapsan occasional further test, the treatment of bacterial diseaseswith vaccines can be guided with practical efficiency bytemperature indications. The higher ranges of tempera-ture are records of depressed indices, which are negativephases induced by excessive administration or productionof toxins, whilst normal or in some degree subnormal

temperatures correspond to a reactive elevation of the index.Just as in logarithms and other formulas we find in a con-

crete form the results of enormous mathematical labourwhich can be used at sight by practical engineers, few ofwhom could perhaps even understand the calculations fromwhich the results are obtained, so it is to be hoped andexpected that laboratory research will yield clinical indicesfor the bedside guidance of the practitioner. And in pro-portion as the results of these minute bacteriological in-quiries become available as a part of general clinical know-ledge and method, so is the relational outlook or perspec-tive of medical practice enlarged and deepened. Perhapsno better illustration could be found of the essential andorganic connexion between hospital and laboratory work,which many shallow-thinking people would wish to divorce.There is, of course, much yet to be accomplished. I donot think we are yet informed as to the opsonic indicationof the greater depressions of temperature. We want, further,to know more than we did 14 years ago, about the effect ofmere temperature in inhibiting or otherwise the bacillaryactivity by which the toxins are produced. I ventured to

express the belief, founded upon clinical experience, that ahigh temperature inhibits bacillary activity and so preparesfor a decline of temperature, and that when the depression issufficiently great fresh bacillary activity is again favoured.This view does not at first sight seem to tally with recentopsonic experience, by which one would judge the resistanceat least to be lowered during high and heightened during lowtemperatures. I am inclined to think that this discrepancyis more apparent than real and will be cleared up by furtherobservations. A high opsonic index is not incompatiblewith an activity of toxin production which may overpower itand again send up the temperature.We also want much further information as to the effect of

drugs, especially of quinine, arsenic, antipyretics, alcohol,nucleins, trypsin, as well as of vital conditions, such as

anaemia, menstruation, the climacteric period, &c., upon the

opsonic index.The value and limitations of the opsonic treatment of

specific diseases are still under consideration, and in

diagnosis I have met with several instances of errors, givingrise to at least much inconvenience and expense to patients,from opsonic or other bacteriological research-results beingregarded too exclusively and apart from the other clinicalfeatures of the case.The whole question of natural or acquired immunity to

specific diseases is a very interesting one. One meets withinstances of persons who, after having visited health resortsfor many seasons on account of pulmonary disease, havewearied of their wanderings and settled in home quarters.With, perhaps, a considerable amount of disorganisationof one lung, their disease at last arrives at a stage ofquiescence. Such patients will now continue in this con-dition for years and perhaps die from a totally differentmalady. I can recall two instances in which, after manyyears, cancer of the breast with internal recurrence hasterminated such cases. They seem to possess a considerablestrength of immunity. I have known severe attacks of influen,zato fail to bring about relapse. Do these cases become immune

1125

by virtue of auto-vaccination, and are we right in regardingthem as automatic and haphazard examples of quiescencebrought about by conditions which are more systematicallyand scientifically secured by the graduated labour conditionsof Paterson ?-conditions, that is, effecting an auto-immunisa-tion equivalent to larger and larger doses of tuberculin untilthe opsonic index for tubercle-whatever that may mean-has’ become steadily high and the patient permanentlyprotected.It is probable that many people experience unconsciousattacks of various acute specific diseases which enable themto resist attacks from subsequent exposure. It occurred tome a few years ago to see in quick succession three cases inwhich, on the strength of a positive Widal report from aresearch society, a diagnosis of enteric fever had beenarrived at in the absence of any other confirmatory sym-ptoms. In one of the cases rooms had already been clearedand nurses secured for the enteric campaign, but thecase proved only a slight one of influenza and the patientwas about his business in three days. The others wereinfluenza and lymphadenoma respectively. Apart from

illustrating the importance of regarding any one sign orsymptom, however valuable in itself, in due proportion withthe other features of the case, these instances were in favourof the view that the patients had been unconsciously sub-jected to the influence of the enteric poison in slight andmerely immunising degree. None of them had been vacci-nated against typhoid fever, but the gentleman to whose caseI specially refer had been in South Africa during the war.Again, one comes across many cases which bear a similarinterpretation, old unrecognised tuberculous depositions,febriculas, catarrhs, anomalous and slight degrees of measles,whooping-cough, or sore-throats so common at the com-

mencement and the decline of epidemics, and which may bespecific enough to prove protective. One often observes thedwellers in an old insanitary house to have for years ex-

perienced no defined illness, yet a new tenant will at oncesuccumb to an enteric or diphtheritic attack. Whether inthese cases any specifically altered opsonic index obtain, orwhether there is some structural change in the avenues ofentry of such diseases-the tonsils, faucial glands, Peyerianglands, bronchial glands, the spleen, &c.-which rendersthem sterile soil for fresh invasion, I have no knowledge.With regard to the permanence of the immunity from

tuberculosis there is a caveat to be entered. No man, in mybelief, however roundly 11 cured," can safely return to thecrowded office or insanitary factory life under which he mayoriginally have acquired his disease. With old lesions in hislungs, however quiescent, he is liable to bacterial invasionand lodgment (other than tuberculous) about the damagedsurfaces, which cause infective congestion or inflammationand thus establish fresh conditions for cultivation oflocalised tubercle bacilli " which are not dead but sleepeth,"the toxins from which will break down his immunity.

I should like to express my sense of the indebtedness ofthe profession to those physicians and surgeons who havedone so much to bring the research work of modern timesinto closer touch with clinical medicine. Many of the mostimportant observations in medicine have been the result ofpatient bedside investigation: Addison’s disease, perniciousansemia, the differentiation of enteric from typhus fever,the recognition of myxcedema, and others might be quoted ;and the physicians of Guy’s Hospital have been conspicuousin contributions of this kind.

I have it in mind that one of the first observations leadingto a symptomatic localisation of nervous lesions was derivedfrom a case in which a dagger thrust had divided a segmentof the spinal cord high up, and the effects of which wereobserved by a great surgeon of the time, whom I cannot atthis moment identify. Our first clear views of the physio-logy and chemistry of the digestive process were derivedfrom observations by Beaumont on Alexis St. Martin. Itmay be that with Claude Bernard and the rise of his schoolof experimental physiologists, a disposition to submitproblems first hand to experiment tended for a time ratherto discourage clinical observation and to induce physiciansto accept physiological teaching for their practical guidance.If so, it was but a momentary ’’ stand at gaze" of apractical profession in obedience to the dominance of aparticular school of thought. Clinical observation had beenbrought into line with physiological research by MarshallHall, the great expositor of physiological tenets as applied

to medicine, who was succeeded by Charcot and HughlingsJackson, the great clinical observers of nervous diseases, andlater still by Victor Horsley and Ferrier, who have so success.fully combined experimental and clinical methods ; and, inthe sense in which I am now speaking, perhaps no one hascontributed more to our exact knowledge of cerebro-spinalanatomy than Sir W. Gowers, by his combined clinical andpathological observations on localised cerebral and spinallesions and the paths of degeneration leading from them.And at the present time the currents of nervous influence,their cerebral and spinal source, and the territories to whichthey lead are as fully charted as are the paths of humanintercourse by land and sea and the countries which theyconnect. Bence Jones and Garrod carried out importantinvestigations into diseased conditions from the chemical andmetabolic side in the patients under their clinical observation,and Dr. F. W. Pavy has, by unremitting laboratory work inconnexion with bedside observation, told us most that weknow of glycosuric maladies, which the experiments of ClaudeBernard elucidated from the more purely experimental side.

I have sufficiently illustrated my text by references tocombined clinical and laboratory examination of blood condi-tions, to which large field a whole course of lectures might be

devoted. I would pass on to allude to the encouragementgiven to enlightened clinical research by the Oliver Sharpeylectures at the Royal College of Physicians, instituted by thegenerosity of Dr. G. Oliver of Harrogate, who has himselfdone so much in searching out the secrets of nature by wayof experiment," both clinically and in the laboratory. Thelatest and perhaps the most important development of thisnewer phase of practical medicine is to be found in theestablishment at Cambridge of a Committee for the Study ofSpecial Diseases, which has now been at work some twoyears. Composed partly of men engaged in practice andpartly of those pursuing scientific research, the object of thecommittee is to investigate important and obscure diseases,receiving a few cases of one sort at a time for a period ofclose observation with all the methods of modern science.This is an example which our great hospitals might wellfollow by the establishment of a research ward for clinicalinvestigation of chronic maladies. It would add strength totheir teaching and be of great service to the community.

It may be thought that I have diverged from my text intoa disquisition about things of which I know but little. Iwould urge, however, on the one hand, that my argument isthat all the factors of medical diagnosis and treatment, how-ever technical and dependent upon separate inquiry andresearch at the hands of experts, must be brought into lineand perspective with one another and must be made com-prehensible to the practising physician before they can be ofreal value, or, at least, of more than scientific interest. Ihave heard it often complained that the discoveries of

Harvey, of Jenner, of Darwin, of Pasteur, of Lister, ofKoch have each in their turn been received with incredulityand hostile criticism. Surely this is more as it should bethan if they had been met with an amiable and supineacquiescence. Hostile criticism is the best advertisementand controversy makes for education. It is right anddesirable that each new phase of science in its bearing upon theart of medicine should be subjected to the fire of criticism, topurify it and weld it into due relation with all other factors.Until it has passed through that ordeal it remains but of

philosophical interest. We have learned much since thefirst days of inoculation for small-pox, and Jennerianvaccination as an institution is only defensible in perspectivewith the facts of the time, the positive facts of the appallingvirulence and loathsome and fatal effects of the disease, andthe negative fact of its actual cause not being then, nor

even now, known to us. It was instituted in hygienicdarkness; in the light of preventive science and with theefficacy of police sanitation and the certainty sooner or

later of the true nature of the disease being discovered wemay foresee the time when vaccination employed in contactareas alone may be adequate for the protection of the com-munity. Had Haffkine’s vaccine been known in the darkand evil days of plague epidemics in this metropolis it

might have been adopted for a disease which has since beenwiped from the slate of Europe by hygienic measures alone.This does not lessen the value of Haffkine’s discovery andthe usefulness of its application, not in place of, but ancillary

to, the more fundamentally important methods of hygiene incontact areas.

1126

It might be arguable, I am inclined to think that it is inthe minds of some, that inasmuch as with the increased

purity of our surroundings we are becoming more and morevirgin soil for specific poisons, we should be vaccinated

against the principal of them-e.g., enteric fever, plague,tetanus, tubercle-to which we are likely to be exposed inneighbourhoods less well guarded than our own. Except asa preventive measure in actual contact areas, it is unlikely,however, that the saving humour and common sense of theprofession will ever entertain the idea of our becoming as itwere such pathological pin-cushions. It is probably wiserto hold immunity in reserve than to risk its exhaustionbeforehand.There never was a period when we could see so

minutely into disease as we can now, and as timeadvances our vision will become still more penetrating; itbehoves us the more to preserve the range and propor-tion of things lest this finer insight may but enable us

"with finer optics given t’inspect a mite not comprehendthe heav’n." This thesis would bear very wide illustra-tion far beyond my time and compass. The brilliantand penetrating search-lights-microscopic, radiographic,ophthalmic, auro-laryngo-spectro-scopic, sphygmographic,cardiographic, not to mention electrophonic methods andothers which I have not yet in mind-with which we are nowprovided must be used with much discretion and not a littleforbearance. All the defects of our poor personalities, bythese trenchant means disclosed, must not always be takentoo seriously and must be regarded in strict relation with

age and other circumstances connected with the case. Thealienist has to content .himself with a standard below hisown or all his friends would be insane I In many instances,as years advance, a cardiac hypertrophy or a mitral murmurmay be for a man’s salvation, and should not then be

regarded as a disease. A great physician to your hospitalonce twitted a friend who was chagrined at having missed apericardial friction with the remark that he might havetreated it." It is rarely wise, except in the emergency of acritical moment, to make a frontal attack upon a highblood pressure. Many a case of renal inadequacyand not a few of senile decadence have suffered fromthis symptomatic enthusiasm. As an American attach6said to an English general who was squanderinghis forces in disastrous frontal attacks, 11 Is there no

way round, general ?" " I am aware that the learned Dr.Richard Mead wrote a chapter On the Disease of Old Age,"basing his thesis upon the graphic description of that" malady " by Solomon. But is old age a disease ? If so, ithad best rest undiscovered with Sir W. Gull’s pericarditis lestit be treated 1 I would rather regard the changes in organsincidental to age as the health of the autumn leaf preparingfor the fall, and in the survey of our inward parts as ageadvances I would urge the importance of a right perspective.

" Il ne faut pas chercher midi a quatorze heures."

An AddressON

BLOOD PRESSURE IN MAN, ITS MEASURE-MENT AND REGULATION.

Delivered before the Cardiff Medical Society on May 6th, 1908,

BY SIR LAUDER BRUNTON, BART., M.D. EDIN.,F.R.C.P. LOND., F.R.S.,

CONSULTING PHYSICIAN TO ST. BARTHOLOMEW’S HOSPITAL, LONDON.

[SIR LAUDER BRUNTON commenced his address by thank-ing his audience for having invited him to address them asecond time.’ On the last occasion he had chosen the subjectof Atheroma. His present address was supplementary to theformer. After mentioning the physical conditions whichwould raise or lower the blood pressure he proceeded :-]The first definite attempts to measure the blood pressure

were made by the Rev. Stephen Hales who connecteda piece of glass tubing with the opened artery of a

living animal and noticed how far the blood rose

in the tube. The next improvement was made byPoiseuille, a Frenchman who substituted a bent tubecontaining mercury for the straight tube of Hales. The

1 THE LANCET, Oct. 12th, 1895, p. 897.

next improvement was made by Ludwig, who added to,Poiseuille’s tube a fine rod which rested on the surface ofa mercurial column, moved up and down with it, and reocorded its movements on a revolving cylinder. It is to

Ludwig and his pupils that we owe a very large proportionof the knowledge which we now possess regarding bloodpressure, and perhaps in these days of active outcryagainst vivisection and of lying statements regarding thecruelties which are said to be perpetrated by those whoemploy the methods of experimental physiology, I maystate that Ludwig’s humane character was so well knownto his fellow townsmen that they elected him President ofthe Leipzig Thierschutzverein, that is to say, of the Societyfor the Prevention of Cruelty to Animals. My old friend,Professor von Basch, who was, like me, one of Ludwig’spupils, spent his winters in physiological research and hissummers as a practical physician at Carlsbad. He had thusa double training, experimental and clinical. His clinicalwork showed him the great need of measuring the bloodpressure in man. This was impossible with the methods

previously in vogue which involved opening an artery. Hetherefore tried to discover a method of measuring the bloodpressure in an unopened artery. It is not always easy totrace the introduction of new methods, especially when theirintroducers and those who have been personally acquaintedwith them have passed away, and so you will, perhaps,allow me to tell you something of the first introduction ofthis method. Professor von Basch was not a member of thePhysiological Society of Berlin but he was taken there onJan. 30th, 1880, by another of my old friends who was also apupil of Ludwig, Professor Kronecker. He there gavethe first demonstration of his method.:I He exposed one

femoral artery of a dog and connected it with a mercurialmanometer. Over the other femoral artery he put a smallindiarubber bag or bulb which was connected with a mer-curial manometer and also with a pressure apparatus whichallowed the pressure exerted upon the artery to be increasedor diminished at will. (Fig. 1.) He then gradually raisedthe pressure and showed that at the moment when pulsationcould no longer be felt in the distal part of the artery, beyondthe bulb, the mercurial column connected with it stood at thesame height as the other one which was connected to theopen femoral artery. In this way he proved conclusivelythat it was possible to estimate exactly the pressure ofblood within the artery. Here again I may mention that ifI were to describe to you my journey from London to Cardifl!to-day I should probably omit to say that I took a ticketbefore I entered the carriage because this is an invariable

preliminary to a railway journey. In the same way allanimals in Ludwig’s laboratory were so invariably narcotisedby laudanum before any operation was begun that mentionof the fact was frequently, indeed, I think generally,omitted in describing their experiments both by himselfand his pupils as in the case of von Basch’s demonstration.The instrument which von Basch used at the meeting of thePhysiological Society, though well adapted for a publicdemonstration, was not at all suitable for clinical work.He therefore devised one in which a mercurial column wasconnected with a tube containing water and covered by apiece of sheet indiarubber at one end. (Fig. 2.) Themethod of using this was to press it upon the radialartery until the pulse was obliterated, so that it couldno longer be perceived by the finger placed on t4aartery beyond the point of pressure. The pressure wasthen read off directly on a scale. But this instrument alsowas very unsatisfactory and unless kept carefully in theupright position was almost certain to get quickly out oforder. He therefore discarded the mercury in favour of ananeroid manometer. To this a small elastic bag wasattached by which the artery could be compressed and theamount of pressure directly read off on the scale of themanometer. (Fig. 3.) The elastic bag originally used byvon Basch was surrounded by a metal ring to prevent toogreat lateral expansion. Potain replaced the metal ring bymaking the sides of the bag of thicker indiarubber. Boththese contrivances (Figs. 4 and 5) may be discarded, and thebag at present used with von Basch’s instrument (Fig. 6) isone of plain rubber. This instrument has the great con-veniences of being very readily portable, not liable to getquickly out of order, not likely to alarm the patient,and it can be used in half a minute, so that the time

2 Verhandlungen den Physiologischen Gesellschaft zu Berlin,Jahrgangr 1879-80, No. 7.