483LEADING ARTICLES

The Expert in CourtWITH the growth of technical knowledge, expert

evidence plays an increasingly important part incivil and criminal trials ; and doctors are more andmore often called upon, for example, to establishthe cause of death or injury, to describe the mentalstate of the accused, and to introduce scientific modesof proof. Unfortunately, British legal procedure doesnot yet enable the expert to give his testimony underconditions that assure its full effect in court. This is

largely because the law treats him simply as a witnessand does not recognise that he should perform a ratherdifferent function. An expert witness may, it is true,express opinions, whereas an ordinary witness mustspeak only to what he has personally heard or seen ;but in every other respect the two are not distinguished.Yet the purpose of technical evidence is unlike that ofother evidence : the expert not only reports facts with-in his observation but must also interpret scientificdata and assess their significance. True, he may notalways be able to offer a complete and unqualifiedscientific judgment, but the more complex and

specialised the questions involved and the researchrequired, the more the tribunal depends on hisconclusions. Where, for example, his evidence is theresult of laboratory work or psychological examination,it can seldom. be checked by judge or jury, and hebecomes in reality an assistant of the court ratherthan a mere witness. But his position as such isneither recognised nor safeguarded by our law.In many countries, and particularly in France and

Italy, the problem of expert evidence has long exercisedboth the legislature and the medical profession ; andthe rules governing the evidence of experts in Frenchcivil actions (which with minor modifications applyalso to criminal trials) were brought up to date asrecently as 1944. Whenever in French legal proceed-ings any question arises which cannot be resolved. mwithout special professional knowledge and experience,the court will charge a scientist or professional manwith the task of furnishing an official expert report.The report is termed " official," not because Frenchcourts are in any way bound by its findings-on thecontrary, they are as free as English courts to acceptor reject any or all of its conclusions-but because theexpert in any given case owes his appointment to thejudge, who selects him from a panel drawn up for thispurpose every year, after consultation, in the caseof doctors, with the medical organisation of the district.Inscription on the panel gives the expert a certainstanding during the trial, and the fact that he oweshis appointment to the court itself and not to one ofthe parties has other important advantages for him.In England, though a witness may often feel that heshould be concerned solely with medical and scientificissues, and not with extrinsic considerations whichbear upon the merits of either side’s case, he cannot

altogether forget that he has been selected and

appointed by one of the parties. Obviously the partywhich has brought in an expert, has taken a preliminarystatement from him, and has undertaken to pay hisfee, will expect him to support, or at least favourablyrepresent, its contentions : and the result may be acontest between expert witnesses, which obliges thecourt to judge between specialists. Sometimes, nodoubt, such clashes of opinion reveal the truth ; and

sometimes it may be salutary for an authoritativevoice to be publicly challenged. French lawyers andmedical men nevertheless agree in thinking it unedi-fying that two sets of experts should propound, onbehalf of their respective parties, diametrically opposedopinions on scientific issues, and in French proceedingsonly one expert is, as a rule, appointed to act.The question or questions on which the expert is

to report must, moreover, be precisely indicated fromthe outset, and with a medical witness may refer onlyto purely medical matters. In accordance with the

predominantly written character of French civil

procedure, the expert’s report is usually prepared inwritten form and must be communicated, or at leastmust be open to inspection by both parties, before thehearing. It falls into two parts : (1) a statement ofany investigations which the expert has carried out,and (2) the conclusions he draws from his expositionof the facts. In this way French law avoids the hypo-thetical questions which in English courts do so muchto befog vital issues, and it enables medical expertsto speak in terms which include inferences, deductions,and conclusions as well as the data on which these arebased. In these circumstances it is only logical thatthe French expert does not assure the court that hewill speak " the truth, the whole truth, and nothingbut the truth "-a formula which is unsatisfactory,as Sir NORWOOD EAST has pointed out, because theexpert may only be able to give an approximateopinion-but merely promises to " give his opinionaccording to the best of his honour and conscience."Members of the medical profession have often beendisinclined to give the categorical answers that seemto be expected of them in English courts, and it iswell known that the expert who deserves the greatestcredit is not necessarily the one who is able to pro-pound his views in the most definite and plausibleform. Here again, something might be learnt from

, the practice in French courts by which, when a medicalexpert is called on to introduce his report personallyat the hearing, great care is taken not to press him toohard for definite and unqualified replies.

All these safeguards help to give medical experts aconsiderable reputation in French courts. Such istheir professional standing and detached position thatjudges are most reluctant to override their consideredopinions : indeed, there is already a positivist schoolof jurisprudence which demands that experts shouldbe sole judges of purely scientific questions submittedto them and that their findings should be conclusive.In this country, on the other hand, though the courtsare beginning to recognise that on medicolegal issuesthey must, to a large extent, depend on the adviceoffered by experienced professional men, the j judges(and juries) still tend to treat expert evidence some-what sceptically. The reason for this attitude is notfar to seek : where choice and nomination, and notleast the examination of the various experts, is leftto the contending parties, the courts all too oftenfind themselves faced with irreconcilable contradic-tions which may, in the most complicated cases,throw them back on their own resources. Some stepstowards better use of the responsible and skilled workdone by medical experts have already been taken bylegislation, such as that providing for medical refereesunder the Workmen’s Compensation Acts ; andunder the present Rules of the Supreme Court wide

484 ANNOTATIONS

powers exist that would make it possible, in a suitablecase, to call on experts to take a place on the benchas official assistants of the tribunal. It is in the employ-ment of experts as assessors rather than as advocatesthat future development seems to lie.

Annotations

FIELD SURGERY

WAR surgery differs from civilian surgery in that mostof it is urgent, that most of the wounds are heavilycontaminated at their infliction, that patients may needto be moved long distances over bad roads soon aftertheir injury or operation, and that conditions of operatingare usually much less favourable" than in peace. The

surgeon’s physical surroundings and the extreme fluctua-tion in the volume of work make his peace-time experience,at times, a positive disadvantage. He will, perforce,have to transgress the accepted boundaries of specialisedcivilian practice; and he may, for example, have insuccession to suture a perforated small intestine, to

put up a fractured femur, and to eviscerate an eye. Hemay have to do this in the face of an unfavou’rablemilitary situation which compels the evacuation of hispatients at the earliest moment. He may be in thedreadful position of having so much to do that the

desperate cases must be left so that those with goodprospect of life may receive attention. The comparativeleisure and elegance of peace-time surgery offers no helpin such circumstances ; and some surgeons may rememberwith what gratitude they read, early in 1940, a smallStationery Office publication entitled Manual of Injuriesand Diseases of War. Though it bore the date" 1918,"and though its readers were men with experience ofcivil surgery, it was studied eagerly because it dealtwith problems which had not been met, except perhapsin Spain, since 1918. It showed why the accepted pro-cedures and techniques of civil life would not necessarilywork in war. This little manual was not officiallysupplanted in the surgeon’s library until the Field

Surgery Pocket Book appeared in 1944, and the final

gathering together of the lessons learnt from 1939 to1945 has now been made in the revision of the FieldSurgery Pocket Book which has recently appeared.!We welcome this as evidence that if, unhappily, the

generation of young surgeons which is growing up shouldbe plunged into a new war, they will not need to relearnby bitter experience the lessons of 1939-45. They willsplit plaster-casts before evacuating their patients, theywill not do primary sutures of wounds on men aboutto entrain for a base hospital, and they will not expectpatients with abdominal wounds to stand a long journeywell within a few days of operation. The new editionis of less than 200 pages, and it will, as its name implies,fit into a side-pocket. Its style is dogmatic because thereis not room for discussion of differing points of viewand because its function is to guide while its reader isgaining experience. Besides the chapters dealing withwounds, there is a brief section on surgery in the tropics,some speculative remarks on injuries by atomic weapons,and chapters on internal derangements of the knee anddisabilities of the feet in soldiers. The book packs animmense amount of authoritative information into a

very small space, and it is clearly written by, or compiledfrom the writings of, men who have had large experienceof what they describe. Its object is admirably summarisedin the last paragraph of the introduction, which reads :

" It may be that many years will elapse before the needfor a field surgery pocket book will arise. Even so, this editionshould not have become obsolete. The policy of earlyadequate surgery was the lesson of the South African War,1. A Field Surgery Pocket Book. H.M. Stationery Office. 1950.

4s.

and some of the teachings of the old masters of 1917 werebeing rediscovered a quarter of a century later. It is the

duty -of those who go, to record the lessons learnt, and ofthose who come, to study them."

HEREDOFAMILIAL TREMOR

THE first systematic account of heredofamilial tremorwas given by Dana in 1887 ; but in Britain and theU.S.A. this relatively common benign disorder receivedlittle attention until it was comprehensively reviewedby Critchley 2 in 1949. Latterly 14 cases have been

reported by Davis and Kunkle.3The disorder is usually strongly familial, a dominant

inheritance being the rule ; and the tremor may startat any age, though

"

anticipation " with onset at earlierages in successive generations is common. Tremor

usually begins in the arms, and in some patients maylater spread to involve the neck and jaws. The charac-teristics of the tremor vary ; the three common typesare : (1) a rapid oscillation resembling that seen inthyrotoxicosis ; (2) a coarser tremor present at restand inhibited by voluntary movement, as with the

parkinsonian tremor ; and (3) an action type not presentin the resting limb but appearing on movement, such asmay occur in cerebellar disease. The tremor is in generalmade worse by emotional stress and fatigue, and it stopsduring sleep. It is not accompanied by any other

physical signs of neurological dysfunction, and the

diagnosis is usually made certain by this fact and bythe family history. The natural history of the conditionis for the tremor to become more pronounced and perhapsspread from one arm to the other over a period of two tothree years, and then to remain unchanged ; but in somecases it may become more severe in later life. The

pathological basis is not known : in the few post-mortemexaminations that have been performed there have

usually been complicating conditions such as cerebralarteriosclerosis, and no definite conclusions can bedrawn from them.There have been various speculations about the

nosological grouping of familial tremor ; the Russian

neurologist Minor 4 suggested that families in whichthis type of tremor occurred were also characterised by’abnormal fecundity and longevity, and he suggested thename of status macrobioticus multiparus for this triad.This curious association is certainly evident at times, asin a recent unreported case where tremor had occurredin members of the patient’s family in at least three

generations. The patient was one of eight siblings, whileher father, who had also suffered from tremor, was oneof ten ; four of the patient’s paternal uncles and auntshad married and had forty-three children between them.There was also a history of more than one centenarianin the family. The association is, however, by no meansconstant and may well be accidental. The suggestionhas also been made that, familial tremor is a " clinical

fragment " of some other neurological disease, suchas paralysis agitans or presenile cerebellar atrophy.Paralysis agitans has been recorded in a family withfamilial tremor,5 as has paralysis agitans developing in apatient who had had familial tremor for many years 2 ;but these isolated instances hardly demonstrate an ætio-

logical relation between the two conditions. Similar

findings have been reported in connection with presenilecerebellar atrophy ; and Critchley and Greenfield 6

suggest that in some cases familial tremor may be a

forme fruste of olivo-ponto-cerebellar atrophy but hereagain the association is rare ; and any fundamentalrelation between the two conditions remains unproved.1. Dana, C. L. Amer. J. med. Sci. 1887, 94, 386.2. Critchley, M. Brain, 1949, 72, 113.3. Davis, C. H., Kunkle, E. C. Arch. intern. Med. 1951, 87, 808.4. Minor, L. Bumke-Foerster Handbuch. Berlin, 1936 ; vol. 16,

p. 974.5. Critchley, M. Lancet, 1931, i, 1221.6. Critchley, M., Greenfield, J. G. Brain, 1948, 71, 343.