MEDICAL EDUCATION

a sound general educa- tion is necessary for the medical as for all other professions. i. in great britain in great britain before admission to a course of training a boy or girl is required to show in an examination of matric- ulation, character and standard that he or she has acquired a respectable knowledge of english, a language other than eng- lish, mathematics and some other school subjects of the candi- date’s own selection. latin is no longer exacted by the general medical council (g.m.c.) although in certain universities it 1s compulsory for students who desire to obtain a medical degree. but the ordinary school subjects are not the only instruments available for the development of intelligence. physics, chemis- try, biology, when well taught also strengthen the mind and develop the faculty of observation which for a doctor is of paramount importance. mx medical education the general council of medical education and registration does not determine directly the requirements of the various licensing bodies, but exercises a measure of control over the doctor’s training by deciding the conditions precedent to regis- tration, first as a medical student and finally as a qualified prac- titioner. since r922 the g.m.c. has required an examination in physics and chemistry be passed by him before registration. the gain is two-fold. his school work more efficiently prepares the boy for his profession, and more time is made available in the brief five years, which is the most.that can be exacted as a mini- mum between registration as a student and registration as a qualified practitioner. the council also allows the student to pass the examination in biology immediately after registration. the curriculum recognised as medical carries the student through a succession of stages which merge insensibly one into the other, until his accumulated knowledge and steadily increasing skill justify the conferring upon him of a degree or diploma which admits him to all the responsibilities of medical practice. it is impossible to over-emphasize the statement that the several steps “‘ merge.”’ they are not stepping stones. no subject is left behind when the passing of an examination qualifies a student to approach the next. the examination tests his fitness to ap- proach subject b whilst still carrying forward subject a. stages of the education.—these stages may be defined as (1) the study of the structure of the body and of its behaviour in health, anatomy (q.v.) and physiology (g.v.), to which two years are assigned. (2) the study of the behaviour of the body when perturbed by abnormal conditions, by malformations, by injury (see pathology), by the invasion of parasites (see parasitology) ranging from ultra-miscroscopic “ germs” (see filter-passing mucrrobes) to intestinal worms, an extension of physiology into the domain of disease. (3) the study of physiological changes which result from the administration of various chemical sub- stances, “ drugs,” already anticipated by the study of the “ drugs” which, in health, various organs pour into the circulation, inter- nal secretions (sce endocrinology). (4) the study of the possibilities of modifying the behaviour of the body, when dis- eased, in a beneficial way by administration of drugs. (5) the proper management of the body in health, preventive medicine. (6) the care of the sick and of women in childbirth. at all periods medical education has been adapted to the knowledge and practice of the age. since pasteur revealed the true cause of the large majority of diseases—the invasion of the body by micro-organisms—the science of medicine may al- most be said to have come into existence. corresponding modi- fications of the medical curriculum have consequently been called for, and many have been adopted—always with a certain lag. since 1910 much has been done in adapting training to the new knowledge and new needs. an important change is the dis- appearance from the curriculum of the subject known as materia medica, a subject which used to make a painful demand upon the student’s memory. long after the date at which doctors ceased to make up their own medicines, compounded of a variety of ingredients, with all the mystery of a professional secret, or wrote equally complicated prescriptions in latin, incomprehen- sible to anyone but a druggist, the student was required to know the methods of preparation and the composition of the drugs of the pharmacopoeia. he was also required to produce a certifi- cate of having attended a course of instruction in dispensing at a hospital or with a qualified medical man or pharmacist. modern pharmacology (sce pharmacology) recognises that the body’s perturbations may be restrained by certain definite chemical substances, many of them produced synthetically. of these the practitioner’s armamentarium contains relatively few. for flavouring and colouring matters he no longer has much use. the object of medical training ——with the exception of the changes already referred to, developments in medical education are rather in the manner of presenting knowledge than in the selection of subjects to be studied. when so much of value must be omitted, every subject included in the curriculum should be taught in the most practical way. it must be made a part of the practitioner’s outfit, which he can never afford to lose. his medical education knowledge of the anatomy of the living body must enable him to see its organs in their relation to one another as clearly as if it were transparent. in some degree dissecting room work has given way to surface anatomy and the study of models and frozen sections; although training in the use of scalpel and forceps is still the only means of acquiring dexterity in the surgeon’s craft. in physiology, during the first vear, the student is in most schools given more practical work than formerly. beginning with the frog and passing on through isolated mammalian organs to the decerebrate mammal, he is brought in his second year more closely into contact with the human body. he learns to use methods and apparatus with which, later, he will investigate the physiological condition of the organs in disease, the greatest changes have been introduced in the third and fourth years of the curriculum. physiology has been extended into pharmacology, an ever-growing body of exact knowledge derived from the study, with instruments of precision, of the effects produced upon guinea-pigs and rabbits by chemical com- pounds of which some, like caffeine and morphine, are vegetable products, whilst others, such as phenacetin, have been prepared synthetically in the laboratory for the express purpose of modifying the behaviour of the body. when used to correct undesirable habits, these various chemical substances, with the apparatus which has been designed for the purpose of studying their effects, belong to the sphere of therapeutics (q.v.). at about this stage in the student’s training, bacteriology (q.v.), a science which is growing so rapidly as to be for the most part relatively new, claims his attention. the micro-organisms which cause disease present biological problems of the highest interest. every medical man needs to be expert in the methods of making preparations for identification with the microscope (see microscopy), of preparing media and of cultivating the various organisms in vitro. and since the effects upon the fluids of the body which they induce can be recognised chemically, a new name, “‘ bio-chemistry ”’ (q.v.), is usually applied to the de- partment of science in which ascertained facts are grouped to- gether. to the physiologist and physician have been opened up the two provinces of serum and vaccine therapy and immunology (see immunity). provision is made for teaching the principles of various kinds of drugless therapeutics, such as treatment with ultra-violet light (see heliotherapy) and with radium massage, and the demonstration of the results obtained in special clinics. pathology (q.v.), formerly the post-mortem examination of patients the course of whose illness had been watched in the wards, has become more of a science. as experimental pathology, it is the study of the physiology of disease. disturbances of function, their causes and progress, are followed by the same methods as if they were variations in the performance of the several organs during health. autopsies confirm or modify views expressed during life regarding tissue changes which were taking place. clinical units —the most notable tmprovement in medical education made during recent years 1s the organisation of clini- cal units. physicians and surgeons still go round their wards at stated hours—usually in the early afternoon—followed by troops of students to whom they point out the features of each case, expound the nature of the malady and explain the reasons for the treatment adopted. but no longer, as formerly, is the stu- dent dependent upon “ walking the wards,” attending lectures and reading about the illnesses of which the cases he has seen are illustrations. the clinica] unit is a far more efficient training centre. its staff consists of a director and three or four assistants. either the director himself or one of his assistants is a whole- time oilicer of the university. to the unit are assigned a numbcr of beds—usually 60 or 7o—in suitable wards with adequate laboratory accommodation in their near vicinity and an ample supply of apparatus for the examination of the patients and for testing their reactions. an out-patient department is included in the unit. in short, it is a school in the sense in which a phys- iological institute is a school. students examine chemically and microscopically the blood and excreta. they make every kind of measurement, and as 849 the wards are open throughout the day thev have the opportu- nity of seeing how patients should be treated, nursed and cared for in every respect. as the teachers of physiology, bacteriology, pharmacology and other subjects visit the clinic from time to time, the student learns under ideal conditions how all that he has been taught combines to fit him for his life-work, the care of the sick and their restoration as speedily as possible to health. when cared for by a clinical unit patients recover more rapidly than they used to do, and in consequence the efficiency of the hospital is increased. the former system contrasted —until comparatively recent times students were required to attend a certain amount of hos- pital practice during their first two yeats, usually six months. this was a relic of the apprenticeship through which aspirants for ad- mission to medical, as to legal and other professional guilds, were required to pass. in britain, this tradition is obsolete at last. no longer is a student required, or even allowed, to listen to bedside disquisitions on maladies of which even the names may be unfamiliar, in terms which carry little meaning to his mind, or to watch the physical examination of organs of which he knows but vaguely the form and situation, and to hear of their perturbations before he knows how they function normally. not until he knows how the body works in health is he shown how disease may disturb its harmony, or taught the remedial measures which should be adopted with a view to aiding nature to set it right. too early contact with patients inevitably led to confused thinking and false inferences which had to be corrected by sub- sequent reading and observation and, it may be added, devel- oped in the tyro a conviction that medical practice consists in “spotting ’’ the disease and administering the drug which will “cure” it. the progressive opening-out of knowledge with the synchronous revelation of ignorance, which is the aim of the modern curriculum, avoids loss of time and secures the highest degree of qualification for the exercise of the medical profession which the limited period of training allows. post-graduate and specialist work.—as a result of the careful allocation of his time the modern student finds that he has less opportunity than his forerunners of paying special attention 10 any branch which may attract him. diseases of the eve, of the throat, of the ear, of the nervous and other organs, are treated with sufficient fullness for the equipment of general practitioners, but not with the thoroughness necessary to make specialists. the student who proposes to specialise must continue his studies after graduation. an increasing number of graduates who do not propose to devote themselves to a single speciality, but wish to make themselves proficient in particular branches of their work, such as gynaecology for example, defer going into practice, or return from time to time to a medical school in order to keep abreast with advances in knowledge and technique. vpost- graduation courses are more numerous and better organised than they were before the war, but they are not yet, in britain, as complete or as intensive as they might be. other countries —in the universities of canada and australia and of most foreign countries, progress has followed the same lines as in britain. a logical sequence of studies and their inte- gration in the curriculum has been the reformer’s aim. in japan the sequence of studies is much the same as in britain; but the minimal length of the purely medical curriculum is four years, following on a course in the preliminary sciences. french medical schools still adhere to the system which they regard as “ natural.” their students are encouraged to attend clinics from the date of their inscription in the faculty, and the relegation of all lectures and laboratory work to the afternoons almost compels them to devote the mornings to attendance in the wards and out-patient departments. binliograrny.—for detailed information consult recent advances in afedical education tn england, a memorandum addressed to the minister of flealth by sir george newman, chief medical officer, and amfedical education, a comparative study, by abraham flexner, ee t1.) united states —in 1900 there were in existence in amcrica 160 medical schools, mostly in fact, if not in form, private ven- tures; even the few schools of high grade possessed meagre 850 endowment and inadequate facilities. by a process of natural selection, the number of schools was rapidly reduced, having fallen in 1925 to 80, and there were grounds for the belief that this number would in the near future be still further reduced. the organisation, endowment and facilities for instruction showed a notable advance. in ro10 few medical schools actually controlled the hospitals in which their teaching was done. sub- sequently there was a distinct tendency to give the university medical schools exclusive and adequate control of hospital facil- ities for clinical teaching and research. harvard, yale, wash- ington and other universities thus came into much more inti- mate relations with the hospitals in which the clinical staffs teach. the city of cincinnati built one of the finest public hospitals in the united states and amended the city charter so as to give the university of cincinnati (a municipal institution) complete control of the hospital for its medical school. on the financial side, public opinion was brought to realise that the university school of medicine is an expensive entcr- prise, for which large investments must be made by the public in both facilitics and endowment. mr. john d. rockefeller gave the general education board approximately $35,000,000 to be used primarily for the purpose of co-operating with institutions in raising large sums for the development of their medical schools, and the late mr. joseph r. delamar gave $5,000,000 each to the medical departments of harvard, columbia and johns hopkins. upwards of $12,000,000 was raised for the establishment of a new medical department at the university of rochester, roch- ester, n. y., and $8,000,000 was raised for the reorganisation of the medical department of vanderbilt university, nashville, tennessee. columbia university is building a new medical school, and the presbyterian hospital, the sloane hospital and the vanderbilt clinic are providing new clinical facilities for the use of the school, the whole involving a prospective invest- ment of $13,000,000; so at cleveland an admirable school and laboratory building has been constructed on a new site on which university hospitals are already being located. in this move- ment the state universities have participated—notably the unt- versity of iowa, which is completing a new plant—laboratorics and clinics—at a cost of $5,000,000. many other endowed insti- tutions also procured considerable sums for improved laboratory and teaching facilities. in respect to organisation the main change in the period was the introduction of the full-time plan corresponding to the eng- lish unit system in the teaching of the clinical subjects. the aim and purpose of this movement are the same in both countries, but in neither had sufficient time elapsed to allow a final verdict to be passed on the merits of the system. the complete satis- faction of the johns hopkins medical school in the working of this plan is shown by the fact that the system, which originally included medicine, surgery and pediatrics, has been extended so as to include gynaecology, obstetrics and ophthalmology. the system has also been adopted in the main clinical branches by the medical departments of washington university (st. louis), yale university, vanderbilt university, university of chicago, university of rochester, the medical clinic of columbia uni- versity, the psychiatric, pediatric and obstetrical clinics of the university of lowa and the neurological clinic at harvard. china.—through a subsidiary board (the china medical board) the rockefeller foundation of new york has established in china a modern medical school. the rockefeller foundation has furnished funds amounting to $8,000,000 to build and equip the peking union medical college, and in addition it was in 1921 supporting the institution on the basis of a budget for the year amounting to $500,000. the institution furnishes two years of pre-medical work, and intended to develop a four-year medical course. the china medical board also aids four other medical schools in china carried on by other organisations. belgium.—the university of brussels had in 1921 planned a complete reorganisation of its medical department. the city, the state and the university co-operated in maturing plans for a modern teaching hospital, and new, well-equipped laboratories on a single site. ws. 1) medical legislation medical legislation.—since rorr statutes have been passed in many countries creating or reorganising the central public health authority. the ministry of health for england and wales created by the act of 1919, took the place of the local government board with all its powers and duties and, as re- gards public health, also those previously exercised by the board of education and other departments. power was further created to transfer from the ministry duties which were not incidental to health. ministries of health have also been established in canada (1919), the union of south africa (1919), poland (1919), new zealand (1920), france (1920) and rumania (1923). a dept. of public health for the commonwealth of australia was created in 1921, and a general directorate of public health in spain, by a roval decree of 1922. zymotic diseases —in australia, new zealand and the union of south africa comprehensive regulations regarding the noti- fication and control of infectious diseases were included; similar regulations were issued in austria (1913), the straits settlements (1915), peru (1916), chile (1918), sweden (1919), brazil (1921) and venezuela (1921). a polish law of 1920 created the office of special commissioner for dealing with epidemics, and a french decree of 1920 instituted a mobile unit equipped with labora- tories, etc., for instant dispatch to parts of the country suffering from or threatened with a disease epidemic. vaccination.—by a law of 1914, vaccination against small- pox (q.v.) becomes compulsory in siam whenever the health administrator deems it necessary; in the straits settlements (1915) it is compulsory, and re-vaccination also can be made compulsory in the face of danger; in france (1915) vaccination and re-vaccination can be made compulsory by decree, but (1918) vaccination is compulsory for state officials. chile (1918) has compulsory vaccination in the first, roth and zoth years of age; in venezuela (1921) there is infant vaccination and re- vaccination every seven years, failure to comply barring from a large number of employments. in poland (1919) there is compulsory vaccination for infants, and again at seven years. in tunis (1922) vaccination against smallpox is compulsory, and also against typhoid, cholera and plague, if there is danger of an epidemic. uruguay (1923) has compulsory vaccination in the first six months, and again in the 1oth and 2oth years. a polish law of 1920 makes vaccination against typhoid fever and cholera compulsory for doctors, nurses, employees at waterworks and for those engaged in other specified callings. tuberculosis.—anti-tuberculosis legislation has been put into force in various directions. tuberculosis schemes and the legislation involved are discussed in the article tuberculosis. the milk and dairies (consolidation) act, 1915, provided, inter alia, for the registration of dairies and the inspection of dairies and herds; and prohibits the sale for human consumption of milk from a cow with tuberculosis or other specified diseases of the udder. the milk (special designation) order, 1922, of the ministry of health instituted the licensing of classes of milk, namely, certified, grade a (tuberculin tested), grade a (non- tuberculin tested) and pasteurised; and prohibited the sale of milk under a designation to which it 1s not entitled. the public health act, 1925, section 62, authorises a court of summary jurisdiction to order the removal to a suitable hospital or institution, of any person suffering from pulmonary tuberculosis in an infectious stage, when a source of danger to others, either from lack of proper accommodation or from failure to observe sanitary precautions. in denmark, laws of 1912, 1918 and 1919 made compulsory the notification of pulmonary and laryngeal tuberculosis by the doctor in attendance, who is also required to instruct those in charge of the patient as to sanitary precautions. a japanese law of 1919 gives power to examine any person whose calling might make him a source of transmission, to forbid the exercise of a particular calling by such, and to forbid or restrict trading in old clothes, old books and other articles which might carry infection. in denmark, compulsory isolation of in- fectious cases is also empowered with certain limitations; and laws of 1918 and 1919 provided for the use of public funds to medical research support hospitals for tuberculosis, sanatoria and convalescent establishments. a french law of 1916 instituted public dis- pensaries for treatment and for giving instruction in anti- tuberculosis measures. a decree of 1920 laid down regulations for the establishment, working and supervision of sanatoria. an italian royal decree, 1919, instituted a central anti-tuberculosis committee, and a swedish royal decree, 1912, regulated sub- ventions to hospitals for treating tuberculosis. venereal diseases.—the english venereal diseases act (1917) prohibits treatment by unqualified persons in areas to which it is applied, when gratuitous treatment has been provided and approved, and prohibits all kinds of advertisements of quack remedies for such diseases. in sweden (1912) an affected person is obliged to obtain and complete medical treatment; the same applies to the union of south africa (1919), where it is also an offence for an infected person to follow certain employments, or to engage such a person in the employment; and to czechoslovakia, where an infectious person may also be removed compulsorily to hospital if necessary, and an examination by a doctor can be enforced where there is reason to suppose that a person is infected with such a disease. in the state of rio grande do norte, brazil, by a decree of 1921, a special service for the prevention of ve- nereal diseases was created, and provision was made for action against charlatans and for diffusing information regarding mod- ern methods of avoiding the contagion. in italy, a royal decree, 1923, approved of regulations for the prevention of venereal diseases, including the examination and treatment of prostitutes. a danish law of 1922 obliges a person suffering from venereal disease, in a stage when it may be communicated or transmitted, to inform the other party to a proposed contract of marriage, and this party must be instructed by a doctor before contracting. the parties must make a declaration of freedom from such disease. the same procedure must be adopted if one of the parties suffers from epilepsy. when there is reason to believe that one of the parties may have disease or weakness of the mind such party must present a medical certificate of mental health and make a declaration as above mentioned. housing.—the british housing act, 1925, infer alia, makes it a duty of the local authority and the medical officer of health to inspect houses, prohibits the erection of back-to-back houses, and gives power to close and demolish houses deemed unfit for human habitation. the public health act, 1925, gives a local authority power to cleanse, disinfect or destroy articles infested with vermin in dwellings, and to oblige a landlord or tenant to cleanse the dwelling; powers are granted for cleansing of the person also. a belgian law of 1919 instituted the national society for housing, amongst its powers being that of destroying unhealthy dwellings; a revising law of 1921 gave power to expro- priate such houses and sites as are required. similar powers were granted to authorities in france by a law of ror5. a law of 1922 codifies the laws relating to working-class dwellings. a peruvian law of 1916 obliges landowners to remove and prevent conditions on their land which are deemed to favour the existence of malaria. infant welfare—the british notification of births (exten- sion) act, 191s, extended the act to areas in which it had not been adopted. a belgian law of 1919 instituted the national work for infant welfare. in france a law of 1917 provided finan- cial help for necessitous women in connection with child-birth, and when the mother nurses the child assistance continues for a period of 12 months. in germany (1922) help is given to women in the same circumstances, insured and uninsured. an english act of 1920 regulates the employment of children, young persons and women in industrial occupations; and a peruvian law of the same year is a similar measure. food.—the english public health (milk and cream) regu- lations, 1912, prohibited the addition of any preservatives to milk intended for sale for human consumption, any thickening to cream or preserved cream or any preservatives to cream with less than 35°% of milk fat; the only permissible preservatives in cream intended for human consumption are boric acid, borax, a mixture of these, or hydrogen peroxide. by an order, 1917, no more than o-4% of boric acid may be added and the cream must 851 be sold as preserved cream and labelled as unsuitable for infants and invalids. public health regulations, 1923, fixed the mini- mum percentage of milk fat in dried milk of various descriptions, and that of milk fat and total solids in condensed milks. con- tainers must declare the contents, and skimmed milk be labelled as unfit for babies. drugs.—most countries have legislated to restrict the use of opium, cocaine and related substances, the english thera- peutic substances act, 1925, regulates the manufacture, sale and importation of serums, vaccines, salvarsan, insulin, etc. other countries have legislated similarly. (r. sc.) medical research.—progress in medical research since i91r can be subdivided according to the branch of medical science into which it falls most naturally. an arbitrary classi- fication, however, has the drawback that many subjects might be discussed equally well under other headings than those in which they are presented. | anatomy first place in this section must be given to the collections of specimens illustrating war injuries and diseases that have been formed by certain museums, notably that of the royal college of surgeons of england. extending to many thousand specimens these collections present a picture of the medical and surgical effects of war in the widest sense,that has never been equalled. other anatomical researches of note were upon the distribution of the absorbents from the lower intestine and upon the caeco- colic sphincter tract. the former offers explanation of many peculiarities of disease in this region and is of value surgically; the latter is a new conception, likens the tract in question to the stomach and supports this contention by numerous refer- ences to several species of lower animals. physiology iormones.—bier found reason to believe that a chemical stimulus (hormone) secreted by the retina initiates the formation of the lens in the larva of triton, and that a hormone formed from bone-marrow underlies repair of bone. from this he argued that repair in general is dependent upon special hormones formed at the seat of the injury according to the type of tissue needing repair. the part played by the nervous system in repair still remains obscure. shock and blood transfusion.—a large amount of work was done upon shock and allied conditions. shock 1s of great com- plexity but sudden removal of large quantities of fluid (blood) with the resulting disturbance of the circulation is a fertile cause. in correspondence with this, treatment by transfusion (see b1loop transfusion) is of the greatest value and the methods of transfusion as well as the substances to be used were made the subject of numerous inquiries. broadly speaking, for surgical shock and loss of blood by haemorrhage, injection of solu- tions of gum arabic are of great value, particularly if a small amount of glucose be added. volume of injected fluid and rapidity of action are fundamental considerations, composition of the injected fluid is a matter upon which some latitude can be allowed, and use of blood is by no means obligatory. on the other hand where transfusion is performed for anaemia (see anaemia) due to disease the character of the injected fluid is of first importance. here, use of human blood ts indicated and it is necessary, by careful examination of patient’s blood and donor’s blood to ensure that they belong to blood groups that are not mutually antagonistic. muscle tone—physiological research of unusual importance was carried out (sherrington, magnus and others) upon muscle tone in the decerebrated animal by means of which tendon and other reflexes received a clearer explanation and afforded in- formation upon many reflex postural responses to stimuli that appear to be voluntary. this line of research supplements ex- perimental psychology, a branch of investigation that has made strides during the past two decades (see psychology). respiration.—in the province of respiration, the relation of lactic acid and muscular exercise to the respiratory quotient 852 has been investigated. under exercise a lactic acid maximum of o-3% in the muscles can be reached in about 30 sec., and this, or rather less, is the longest time that maximal exertions can be kept up. for these short maximal efforts there is reason to believe that carbohydrate alone is used by the muscles. regula- tion of rhythmic respiration, from experiments carried out on cats, appears to depend upon the action of an inspiratory mechanism, the apneustic centre, at the level of the striae acusticae, an expiratory mechanism just below it, both of these centres being controlled by the pneumotaxic centre which is situated in the upper half of the pons. the actual stimulating agent is carbon dioxide. other discoveries —very many subjects of inquiry must be passed over here, e.g., discovery of rhythmic contractions of capillaries discovered by means of a special modification of the microscope; the behaviour of the spleen in poisoning by carbon monoxide; the action of lead upon red blood corpuscles; researches on bilirubin and urobilin and other pigments in relation to jaundice; on “ buffering ” of blood whereby the addition of a given amount of acid to blood is represented by a smaller change in reaction than would occur in simple watery solutions because of the existence of weak basic salts of carbonic and phosphoric acid, especially in the red corpuscles; and numerous investigations upon the action of insulin upon blood sugar and other con- stituents of the body as well as upon the interaction of insulin and other endocrine secretions. | energy expenditure —of more general interest is a research carried out upon the energy expenditure in sewing with a machine and hemming by hand. careful measurements were made by means of the respiration calorimeter, but one most instructive result is that influenza exerts a depressant influence on energy output during rest when the patient has apparently recovered completely. in the case of the woman made the sub- ject of measurement for five weeks after her apparent complete recovery, with the body weight returned to normal, energy expenditure was 4% lower than before the illness. tissue cullure-—minute portions of chick and duck embryo heart have been cultivated in special glass cells. under suitable conditions these portions of tissuc live, grow and beat rhythmi- cally in the culture medium for prolonged periods. if two portions of heart from the same species are placed in the same culture cell, each beats rhythmically at an independent rate until the masses fuse by growth when the beats become synchronous. if in the experiment the two portions are chick and duck, fusion by growth may occur but independence of rhythmic contraction persists (see also article tissue culture). as an example of information obtainable only by use of ap- paratus of extreme accuracy, katz showed from a study of the curves of right and left intraventricular pressure and of aortic and pulmonary artery pressure that during normal experimental conditions right and left ventricular systoles and also their ejection phases neither begin nor end simultaneously and are, as a rule, of unequal duration. bio-chemistry insulin.—much of the research falling into this categorv is concerned with the minute physical chemistry of the cell and therefore is of a fundamental character though hardly suitable for analysis in this place. an important practical result of laboratory work consisted in a simplification of the method of preparing insulin (q.v.) whereby a larger amount of the material of a higher potency was prepared from a given amount of raw material in less time and at smaller cost. insulin forms a picrate when freshly ground pancreas is mixed with solid picric acid. the insulin picrate is extracted by means of acetone. by this dis- covery the cost of insulin treatment of diabetics has been reduced to one-third or less. vitamins.—vperhaps the most striking subject upon which bio- chemical investigations have been conducted during recent years has been that associated with accessory food factors (vitamins) and food deficiency diseases. investigation of beri- beri, a nutritional disease associated with various nervous and medical research paralytic symptoms, which occurs in man and can be induced in pigeons by feeding exclusively on polished rice, showed that addition of a minute quantity of the milling was sufficient to prevent onset of the disease or cure it if in existence. then followed investigations into the causation, prevention and cure of scurvy and inquiries into the factors underlying growth of the body generally or of special systems (e¢.g., bone in rickets). it cannot be said with certainty that rickets depends exclusively upon absence of a special vitamin, for other factors, such as a sufficiency of calcium and phosphorus, are necessary. moreover, sunlight, particularly the ultra-violet portion of the spectrum, is no less essential than due provision of the requisite vitamins for production of that normal growth of the body of which normal growth of bones is but a part. asa result of the entire series of investigations upon accessory food factors, it may be said that at the present time fat-soluble vitamin a and water-soluble - vitamin b are regarded as being bound up with processes of growth and in addition there are anti-scorbutic and anti-beri-beri vitamins. these vitamins have been found in a great variety of animal and vegetable substances and the amounts present vary within very wide limits. their nature is unknown, and the most certain points in connection with them are the minuteness of quantity in which they are present and the potency of their activity. as to their origin the suggestion has been put forward on experimental grounds that they are compounds of high energy content produced by the influence of ultra-violet light, but this hypothesis cannot be regarded as proved, indeed, some experi- mental observations are against it. diagnostics radiology (see radiotierapy and rontgenology).—on its diagnostic side, quite apart from the use of contrast meals and injections opaque to the rays, it is now possible to produce tar better radiographs with exposures measured in fractions of a second than were possible at the beginning of the century with exposures lasting minutes. this is largely due to the employment of x-ray tubes in which the anticathode is a mass of tungsten, heated by an independent current. for treatment, in order to approximate the wave-length of rays emitted by the x-ray tube to the wave-length of the gamma rays of radium, apparatus has been produced with a voltage in the region of 200 kilovolts. so far this tvpe of apparatus is employed chieily in the treatment of cancer. during the routine examination of large numbers of cases various anatomical peculiarities have been observed and some hitherto unknown morbid processes in bone have been described. radiology has also proved useful in study of the physiology and pathology of the heart and great blood vessels, in pulmonary conditions, notably tuberculosis and bronchiectasis, in diagnosis of renal and biliary calculi, and it has been sug- gested as a means of diagnosis when perforation of a gastric or intestinal ulcer is suspected. the intentional injection of oxygen or air into the peritoneal cavity as an aid to radio-diagno- sis has been employed somewhat extensively; it is stated to be devoid of risk and renders diagnosis of fluid or solid masses relatively easy. the use of radium (sce cancer; rapium) is confined chichy to the treatment of cancer, but in some conditions of skin, ¢.g., naevi, and in certain uterine conditions it has a well recognised applicability. therapeutic use—other forms of radiant energy, sunlight (heliotherapy), mercury-vapour quartz lamp, carbon arc, radi- ant heat, all of which depend upon the presence of ultra-violet light in the first instance and warmth in the second, are employed therapeutically to an increasing extent. a disadvantage under which x-ray and ultra-violet forms of treatment labour is the absence of a satisfactory standard of dose. sabouraud’s pastille is only reliable for “soft” radiation. the “ skin erythema dose” is unsatisfactory because as used in france it is two and a half times as great as the ‘* hauterythemiosis ” of the germans. even in german institutions the erythema dose varies between 285 r units and 1,120 r units (allartius). eficcts of radiation —numerous researches have been made on the effects of radiation, particularly the gamma rays of medical research radium, upon cells and tissues of the animal body, plants, seeds, bacteria, protozoa. it has been shown that the cell in division is more vulnerable than the cell at rest and that there exists a wide range of radiosensibility amongst animal cells and_ tissues. amongst the most radiosensitive are the lymphocytes. so far as composite tissues are concerned the intestinal mucosa is highly radiosensitive, exposure of the abdomen to unduly heavy dosage leading to excessive formation of mucus, mucoid degeneration, intestinal haemorrhage, paralysis of intestinal muscle, desquama- tion of large tracts of mucosa and death from toxic absorption. while there is universal agreement that, directly or indirectly, rays produce injurious effects upon cells there is doubt whether smaller doses do not stimulate the activity of cells. opinions are divided upon the point, but the failure to observe any but in- jurious effects may depend upon the fact that the experimenters have not reduced the amount of radiation they employed to sufficiently low limits. in the case of ascaris ova increase in rate of division was not observed until the amount of radiation re- ceived by the eggs was reduced to that derived from about one ten-millionth of a milligram of radium bromide for a period of about 30 hours. pathology fhistology.— morbid histology has been in some measure at a standstill, although during the war it was employed extensively in striving to unravel the pathology of war nephritis, gas gan- grene, gas poisoning and, indeed, of any novel pathological con- dition. its most striking success was in reference to the mode of extension of gas gangrene from the seat of infection. the action of the toxin secreted by the infecting bacilli extends along the muscle bundles far in advance of the bacilli themselves, produces glassv changes of the muscle fibres correlated with a loss of con- tractility that can be demonstrated on the operation table and is a necessary precursor to advance of the bacilli themselves by multiplication. these observations were the prelude toa radical modification of the surgery of the condition and a definite im- provement in results. bacteriology.—in bacteriology (q.v.) a useful step was taken by the medical research council in forming the national collection of type cultures at the lister institute. begun in 1920 it now contains more than 2,000 living strains of bacteria, protozoa and fungi, available for workers in widely different lines of research. experiments upon the conditions under which bacilli, particu- larly the sporing anaerobes of tetanus and gas gangrene, exert pathogenic activity showed that if washed clear of toxin and inoculated without contaminating substances they remained inert. multiplication, followed by manifestation of the ordinary disease phenomena, occurred only if they were injected along with toxin (not necessarily their specific toxin) or with some solid particles such as lime or silica. in other experiments the presence of silica exerted an important influence on the multiplica- tion of tubercle bacilli in the tissues. diphitheria.—important observations were conducted in many countries upon the so-called schick test as a means of diagnosing susceptibility to diphtheria (see infectious fevers). hf a minute quantity of diphtheria toxin, highly diluted, were injected intradermally in man there occurred a patch of redness locally about 2 cm. in diameter in certain persons, whereas in others the injection was without effect. heating of the toxin destroys its power of producing this effect. further search indicated that in those persons who are negative, diphtheria antitoxin is present in the blood serum, whether naturally, or as the result of having passed through an attack of diphtheria, or of gradual immunisa- tion owing to the fact that the person is a diphtheria carrier. in schick-positive persons there is absence of antitoxin and there- fore the injected toxin is not neutralised and produces its pathological effect. subsequent examination on a large scale showed that the reliability of the test was of a high order. the natural corollary is that during an epidemic all schick-positive persons should receive a prophylactic treatment with diphtheria antitoxin. later work showed that diphtheria “ anatoxin,”’ 2.e., toxin detoxicated by addition of formaldehyde and exposure to 853 a temperature of 37° c. for a few weeks, was equally efficacious in producing immunity. scarlatina.—by a similar process of reasoning the two dicks in america introduced an intradermal diagnostic test for scarla- tina, the toxin being derived from broth cultures of a variety of haemolytic streptococcus found in the throats of scarlatina patients and believed by some to be the cause of the disease. so far the dick test is not on such firm ground as the schick test. nevertheless some authors have expressed their view that the test is of much value in determining susceptibility or insuscepti- bility to scarlatina and that an anti-scarlatinal serum prepared by means of the haemolytic streptococci is in many instances efficacious in immunising the dick-positive individual and rendering him negative on subsequent intradermal tests. tuberculosis —a further extension of the principle has been applied in the case of tuberculosis (q.v.), but the work is still in its earlier stages and the time is not ripe for dogmatic statement. from time to time papers are published indicating that antibody formation is not a universal function of the tissues but that there are special sites for its formation. so far there is no consensus of opinion on the subject nor are the instances adduced sufficiently marked to be convincing but it is certain that variations occur in local resistance of the tissues to infection. the most recent suggestion is that antibody formation is a function of the reticular endothelial system. tularaemia.—a hitherto unrecognised disease was described by mccoy in ro12 when investigating ground squirrels in tulare county, california, that had been attacked by a plague-like disease not caused by b. pestis. since that time it has been found widely in the united states and was definitely recognised as affecting man in 1914. since 1914 tularaemia has occurred in at least nine laboratory workers engaged on investigations with b. tularense. the micro-organism is an exceedingly minute cocco-bacillus and it is considered that infection in man was by inhalation or by a blood-sucking fly. transmission from rabbit to rabbit occurs by the rabbit louse and the rabbit tick, neither of which bites man. dental caries —a bacillus (b. odontolyticus acidophilus) has been isolated from carious teeth and in pure culture forms sufficient acid to dissolve the enamel. undecayed teeth placed in such pure cultures for a period of weeks show loss of enamel at spots and local growth of the bacilli along the dental tubules. microscopically the appearance of this artificial caries is identical] with that of natural caries. botulism.—numerous papers have been published upon botulism, a form of severe food poisoning (q.v.) dependent upon an anaerobic bacillus (b. botulinus). the nervous system is pro- foundly attacked by the toxin, difficulty of vision, dilated pupils, ptosis and paralyses being among the earliest symptoms. the toxin differs from other toxins in being pathogenic when ad- ministered orally; it is absorbed in the stomach and upper duo- denum. an antitoxic serum has been prepared and is useful in treatment. this form of food poisoning was originally associated with sausages but occurs in connection with a great varicty of foods. most of the recorded cases have occurred in america. spirochactes—during the war there occurred in flanders amongst the men in the trenches a severe form of disease asso- clated with jaundice and haemorrhage which was traced to a spirochaete similar to or identical with sp. icterohaemorrhagtca, which in japan infects rats and is transmitted by them to man. the same organism was found in the rats infesting the trenches. syphilis —in the case of another spirochaetal disease, syphilis (sce venerfal diseases), brown and pearce succeeded in trans- mitting the disease to rabbits by intratesticular inoculation and showed the close resemblance of the pathological and clinical manifestations to those met with in man. by a prolonged series of experiments on rabbits pearce answered in the negative the jong debated question whether yaws and syphilis are manifesta- tions of a single disease. much work has been done on the wassermann reaction. all doubts are not set at rest nor is the behaviour of the reaction completely understood, but it has stood the test of time and is considered of some diagnostic value. 854 in the investigation of spirochaetal diseases caution in de- duction from experiment is shown by the fact that spirochaete- like bodies are to be found in the lateral ventricles of normal monkeys, rabbits and guinea-pigs. only after animals that had been injected long previously with material from disseminated sclerosis (which is regarded by most authorities as of syphilitic origin) had been found to present these bodies in their lateral ventricles, was their existence in normal animals also discovered. typhus.—in typhus and trench fevers minute parasites were discovered belonging to the group now named rickettsia. for a short time the relation of the rickettsia to the disease was in doubt, but largely owing to the work of bacot, an eminent entomologist who contracted typhus during his investigations and died therefrom, it is now recognised that both diseases de- pend upon the presence of varieties of rickettsia, and that these parasites are conveyed from patient to patient by body lice. one of the most delicate manipulative operations ever attempted, and actually carried out with brilliant success by bacot, was the filling of the rectum and intestine of lice with rickettsia-infected blood by means of a fine capillary glass tube. bacteriophage—an interesting phenomenon called after d’herelle, its discoverer, has attracted much attention. when working with certain cultures of intestinal bacteria d’herelle observed that on occasions culture apparently failed, the broth remaining quite clear. subsequently he found that addition of a minute quantity of one of these clear fluids to a culture tube, cloudy with growth, was followed by clarification of the latter; as little as one part in a million was suflicient. he considered that he had obtained evidence of a filter-passing ‘‘ microbe bacterio- phage ” and obtained the phenomenon by successive culture from intestinal contents, sewage, soil extracts. this clarifying power is a property of leucocytes, tears, nasal mucus, eggwhite and other substances. from the first the filter-passing microbial explanation met with opposition, many authorities regarding the phenomenon as being due to the action of an autolytic enzyme, or a catalyst causing the micro-organisms to produce autolytic ferments. later, fleming described a somewhat similar phenomenon by means of a special micro-organism that he isolated (af. /ysedeik- ficus). this organism in thick suspension is in a few minutes completely dissolved by tears in a 1~9,000 dilution and using it as an indicator he found evidence of the lytic principle in nearly all tissues of the body, but not in urine, cerebrospinal fluid or sweat. in the vegetable kingdom he found it in the turnip alone. it is doubtful whether there is a single lytic substance or more than one. the essential difference between this and d’herelle’s phenomenon is that the former cannot be transmitted in series. fleming therefore speaks of it as a “ lysozyme,” and points out that some bacteria are sensitive to lysozyme action and others not, thus raising the speculation whether the pathogenicity of bacteria may be determined by the absence of lysozyme. filter-passing microbes —since t905 papers have appeared from time to time in medical literature on the “ filter passer ” or “ filterable virus ’’ (see filter-passing microbes). a series of morbid conditions is now recognised with more or jess certainty as being due to a virus so minute that it passes through the pores of a porcelain filter, or in some cases is beyond the lowest limits of microscopic vision. of these diseases rabies, vaccinia and perhaps, variola are the best known. in lethargic encephalitis and herpes evidence is tending in that direction but is not con- clusive owing to the discovery that laboratory animals mainly used for this type of work (monkeys, rabbits) may under normal conditions present appearances in their brains that have been regarded as evidence of experimental transmission from man. dengue has been added to the list, while the so-called mosaic disease of the tobacco and tomato plants (see plant pathol- ogy) is stated to be due to a filterable virus, and distemper in dogs may show a like origin. in addition a transmissible filter-passing virus has been recognised in the rabbit; at first this virus was thought to be the cause of varicella but it is now recognised to be the cause of a naturally occurring infection of the rabbit. medical research gye and barnard have described and photographed by means of ultra-violet light, respectively, a filterable virus derived from certain malignant tumours, following in this direction the pioneer work of rous on chicken sarcoma. finally, in the opinion of some authorities the cause of influenza (see influenza) is not pfeiffer’s b. influenza, this being merely a usual concomitant, but is in reality a filter-passing virus that has not yet been deter- mined with certainty. obstetrics and gynaecology eclampsia.—the exact pathology of eclampsia has not yet been solved. obata, as the result of injecting mice with extracts of human eclamptic placenta, considers that it is an intoxication by placental poisons made possible by a weakening in its normal capacity of neutralisation on the part of the maternal blood. treatment of the condition on conservative lines has recently gained ground against more radical measures, and control of con- vulsions by hypnotics with venesection and administration of oxygen have replaced operative procedures. under these con- ditions the previous mortality has been reduced by more than 5° per cent. fibroids.—the chief direction in which change of view is tak- ing place among gynaecologists is that of the treatment of uterine fibroids. the old method of curetting has given place in large measure to hysterectomy, which in turn may be destined to give place to radiological treatment in a large proportion of cases. in several important gynaecological clinics on the con- tinent surgical treatment of uterine fibroids is the exception in an uncomplicated case. medicine anaemia.—in pernicious anaemia (q.v.) it has been shown that one of the cardinal features is an increase in the mean diameter of the red cells which is independent of the degree of the anaemia and persists through the course of the disease. on the other hand anisocytosis increases with the anaemia. in the remissions which occur naturally or after splenectomy, though the haemo- globin may rise there is little change in the diameter of the red cells. in treatment transfusion has been found of little value, but benefit has resulted in some cases from removal of a portion of the bone marrow from the tibia. apparently removal of some of the bone marrow acts as a stimulus to regeneration of marrow and therewith of the blood cells that are needed by the body. purpura is described as being of two varieties (1) that which is dependent upon destruction of blood platelets; (2) that which occurs in anaphylactic conditions and is due to direct injury of blood vessels. in the platelet variety a blood platelet antiserum has been prepared and is of therapeutic value. heart diseases.—dtseases oi the heart and great blood vessels have been studied by means of the electrocardiograph and numerous conditions, particularly heart block and those in which the nervous mechanism of the heart beat is concerned, have been investigated. systematic examination of recruits in whom cardiac symptoms developed during early training resulted in a clearer perception of those abnormalities of heart action which were transient and of little importance as distinguished from those which were significant of disease. cerebrospinal meningitis —cerebrospinal meningitis (q.v.) and lethargic encephalitis (¢g.z.) have received much attention. in cerebrospinal meningitis it has been shown that three, possibly four, different types of meningococcus occur and that antiserum treatment to be successful must be homologous. epidemics could usually be traced to a carrier and the chance of their occurrence was greater where men were confined in a relatively narrow space, e.g., barracks. a special method of treating carriers by means of inhaling chloramine-t was instituted with some success. in the case of lethargic encephalitis, it appears probable that the cause will be found to be a filter-passing virus. herpes.—in the case of herpes in rabbits and herpes in man, including herpes zoster, it has been found possible to transmit keratitis and some other special conditions from animal to animal and man to animal by means of a filter-passing virus. medical service, army when this has occurred microscopical appearances are found in the nervous system apparently identical with those met with in lethargic encephalitis. the whole question, therefore, is in an unsettled condition. liver cirrhosts.—an interesting observation is that a form of progressive degeneration of the lenticular nucleus occurs which is associated with hepatic cirrhosis. since its first description by wilson in 1912 over 70 cases have been described but the patho- logical agent remains completely unknown, though there are indications that the liver is the seat of the primary pathological process. clinically the symptoms are chieily cerebral and the hepatic cirrhosis which is so constantly found at autopsy is usually latent. general paralysis of the insune—in the case of general paralysis of the insane, a form of treatment that has been advocated is inoculation with benign tertian malaria which is then treated with quinine. maniacal and early cases have been found to respond to this treatment best. intelligence, articula- tion, writing and equilibrium improve markedly, but defects of character and manners remain. some cases may even be able to return to responsible duties. advanced cases merely remain stationary. the idea underlying this treatment is that the malarial parasites stimulate the body to the formation of spirochaetal anti-substances. respiratory diseases ——in the province of respiratory diseases, gas poisoning necessitated urgent investigation from the com- mencement of t9r5. an intense oedema was produced which blocked the finer air passages and in its minor degrees led to a widespread bronchopneumonia. variations were met with as the nature of the gas used was changed, but from the respiratory point of view at least the phenomena were fairly constant. in pneumonia, experimental work on monkeys showed that four types of pneumococcus occur and do not protect against one another. a sthma.—work on asthma has shown that in a large propor- tion of cases, if not in all, the disease is of an anaphylactic nature, an intense reaction being produced in the bronchial mucous membrane of a person sensitised to some particular substance of protein origin. determination of the particular substance in any individual case may be lengthy, but if it be determined there is a possibility of successful treatment by gradual immunisation. tuberculosis —in tuberculosis (¢.v.) two important methods of treatment have been suggested. in one, an endeavour has been made to increase the antagonising cells in the body by repeated irradiation of the spleen. this organ is a storehouse for lymphocytes and it is known that the lymphocytic content of the blood can be raised by repeated small doses of x-rays. the method has not as yet a great following. the other method is by administration of a gold salt [au(s203)2nag] named “ sano- crysin’’ by mallgard, originator of the method. the underlying idea is not purely chemotherapeutical for it is held that the poison- ous action of the organisms killed 77 vivo by chemical means is neutralised by an antiserum. the experimental work was carried out in denmark and has been confirmed and extended in this country. careful selection of cases must be made when applying sanocrysin to man as the reaction in pulmonary tuberculosis may be very severe, but with due precautions great benefit may accrue. diabetes.—in the case of diseases of endocrine origin the out- standing example of advance is afforded by the insulin (q.v.) treatment of diabetes (¢.v.). the pathology of the condition was fairly well known but the great achievement of banting and his collaborators was that they succeeded in isolating the material in sufficient quantity for therapeutic purposes. numerous re- searches have been undertaken in the endeavour to simplify the treatment but it still remains necessary for insulin to be injected intravenously and repeatedly in severe diabetes. goitre.—the relation of iodine to endemic and to exophthalmic goitre (g.v.) has been investigated. a close relation between the cellular condition of the thyroid and the amount of iodine has been demonstrated and it is held that relative or absolute defi- ciency of iodine is the immediate cause of simple goitre however 855 ‘this deficiency may be occasioned. treatment by internal administration of iodine has met with much success. success has also been claimed for radiological treatment and for surgery in cases in which iodine and other medical treatment has failed. paratyphotd—description has been given of a paratyphoid epizootic in a flock of sheep with a consequent human epidemic of paratyphoid: (40-50 severe cases with four deaths) that occurred in the essen district. b. paratyphosus b. was isolated from the sheep’s flesh and from the patients’ stools. it was not here a case of contamination but the as suffered from the same disease as the human beings. a peculiar disease has been occurring since july 1924 among the fisher folk of the frisches haff, the great freshwater lagoon of east prussia. many eueecations were put forward as to its aetiology but finally it was traced to arsenic freely contained in the waste water of two cellulose factories which was pouring into the haff in large quantities. racial blood indices —on the basis of observed peculiarities of group ii. and group hi. red blood cells, another research would group mankind according to their racial blood index (sce races of mankind). analysis of the large amount of material | accumulated since r919 suggests that so far as blood groups are concerned races fall into six divisions strikingly different in type. these six divisions are european, intermediate, human, indo- manchurian, afro-south-asiatic and [acific-american. no better indication could be given, than this last example, of the wide range covered by medical research. (w.s. l.-b.)}