wards of St. Thomas's Hospital, as to excite the greatest alarm. No modern surgeon would allow a case of erysipelas to be in the same ward as other patients who have either undergone or are about to undergo operations. In the winter of 1851 erysipelas broke out in one of the wards of University College Hospital, and is thus described by Mr. Erichsen: "The hospital had been free from any cases of this kind for a considerable time, when on the 15th of January, at about noon, a man was admitted under my care and placed in Brundrett Ward. On my visit, two hours after his admission, I ordered him to be removed to a separate room, and directed the chlorides to be freely used in the ward from which he had been taken. Notwithstanding these precautions, two days after this a patient from whom a necrosed portion of ilium had been removed a few weeks previously, and who was lying in the adjoining bed to that in which the patient with the erysipelas had been temporarily placed, was seized with erysipelas of which he speedily died. The disease then spread to almost every case in the ward, and proved fatal to several persons who had been recently operated upon." Quite independent of wounds there are a number of cases on record in which persons in contact with cases of erysipelas have been affected, and the inference seems a fair one that they took the disease through the lungs. The incubation period when erysipelas is inoculated varies from fifteen to sixty hours. (326) Disinfection after Erysipelas. It has been found very difficult in certain cases to destroy the contagion of erysipelas. For example, the old Dreadnought was so saturated with it, that it was found ne it as a hospital ship. Hence a hospit cases of erysipelas should be treated When the disease occurs nj to cease using which has had igorous manner. agated tion of disinfection will suffice. In investigating an epidemic of erysipelas particular attention should be paid to the drainage and to the abatement of nuisances, for it is ever to be remembered that erysipelas is a septic disease and is intimately connected with uncleanliness. DIPHTHERIA. Diphtheria is a micro-parasitic disease, affecting primarily the mucous membrane of the fauces and larynx, but it may also develop on other mucous surfaces, or even in wounds. The microorganism develops a poison at the seat of the infection, one of the most striking effects of which is paralysis—but the latter is not constant. (327) Mortality from Diphtheria. From 1855-80, a period of twenty-six years, there have been registered 89,603 deaths from diphtheria in England and Wales, which gives for those years an average death-toll of 3,446 annually. More females die than males; this excess is real, and not to be accounted for by the excess of female population. The deaths from diphtheria among the female population are 12 per cent. above the male population, whereas the number of females living exceeds that of males by 5 per cent., leaving an excess of 7 per cent. which cannot be attributed to the disparity of the sexes. (328) Geographical Distribution of Diphtheria in England and Wales. This has been carefully studied by Dr. Longstaff (17th Annual Report Local Government Board. Supplement.) He has taken his facts from the abundant statistics of the twenty-six years ending 1880, and has graphically displayed in a shaded map the local mortality; the depth of tint being proportional to the legree. The small fatality of diphtheria in Devonshire, Cornwall, d the Midland counties, contrasts in a striking manner with the ickness of Norfolk, the eastern counties, and the dark tint of les. He shows that diphtheria has always displayed a tendency to prevail in sparsely-populated districts rather than in centres of population; as years have gone on, this tendency has become less and less marked, so that there has been a progressive tendency to equalize the special mortality in urban and rural districts. To sum up in nearly his own words the result of this inquiry :—Whatever units of area are taken in the examination of the geographical distribution of diphtheria in England and Wales, the same general results are arrived at. The distribution of diphtheria is apparently sui generis, the mortality from the disease clearly is not regulated by the same causes as influence the general mortality, certainly density of population does not favour it. This disease appears rather to have a preference for special districts, the great majority of which may be described as rural, and which have but a small proportion of their people living in towns; indeed several of these districts, notably Rothbury, Solihull, Hailsham, Petersfield, Ledbury, and Tenterden, have such a very low general death-rate (varying from 153 to 177 per 1,000), that they fairly claim to be amongst the healthiest areas in England. On the other hand, whilst among those districts which have to a great degree escaped the ravages of diphtheria there are some notably healthy areas, such as Farnham and Andover (with death-rates of 167 and 17.7), there are also a number of towns of medium or large size, some of which, such as Leigh, Bolton, and Wigan, have high general death-rates, ranging from 23.5 to 27·1. The geographical distribution of the other diseases is totally different to that of diphtheria. That summer diarrhoea is especially a disease of towns is a familiar fact to which attention has repeatedly been called by the Registrar-General. Measles is especially fatal in London; scarlet fever is most common in the mining and manufacturing counties-Durham, Yorkshire, Northumberland, Staffordshire, Warwickshire, Cheshire, Lancashire, Monmouthshire, and South Wales. Fifty-seven per cent. of the deaths of males and 51 per cent. of the deaths of females occur in the first five years of life; in the next five years 25 and 29 per cent. respectively, while after the forty-fifth year is reached only 25 per cent. of the deaths of males, and 2 per cent. of the deaths of females takes place (Longstaff). The average deaths per 1,000,000 during the twenty-six years mentioned were for males 157, for females 168. (329) Researches on the Bacteriology and Pathology of Diphtheria. A number of competent observers have, during the last ten or twelve years, devoted themselves to researches on the nature of diphtheria. The student will find an excellent study of these researches up to 1884 in Loeffler's classical paper published in the Mittheilungen des Kaiserlichen Gesundheitsamte, Berlin, 1884. Especial value attaches to the researches of Oertel,1 Loeffler,2 and Klebs.3 Loeffler, Klebs and Oertel agree in finding on the diphtheritic surface a large number of micrococci and various non-pathogenic forms of micro-organisms; some of the micrococci seem to agree with the characters of the septic kinds and penetrate more or less into the mucous tissue. These, when isolated by cultivation, may produce in animals abscesses or a kind of pyæmia and death, but do not produce diphtheria. On the other hand, a micro-organism first carefully described by Klebs, may be considered the bacillus of diphtheria. These bacilli are 64 μ long and 11 μ broad, they have one or both ends swollen. They have no power of selfmovement. They are intensely stained by methylene blue. Spores have not been definitely observed, and since it is found that when exposed for half-an-hour at 60° C. the life of the bacilli is destroyed, this behaviour to heat is not consistent with the presence of spores. To propagate the bacilli by artificial means in cultures, a temperature a little above 20° is necessary. Loeffler considers them capable of retaining their vitality for three months. Inoculated in various ways into mice or rats, both species are found to possess immunity. On the other hand, small birds, guineapigs, fowls and pigeons may all be successfully inoculated; fowls are less sensitive than small birds. Loeffler made one experiment on a long-tailed Java monkey, the result was negative. Possibly diphtheria may be communicated to the anthropoid apes, for there is a case on record of a chimpanzee dying from true diphtheria in the Hamburg Zoological Gardens.* The general effect of inoculating an artificial cultivation of the 1 See M. J. Oertel. Die Pathogenese der epidemischen Diphtherie. Leipzig, 1887. Op. cit. 2 3 Klebs. Archiv f. experimentelle Pathologie u. Pharmakologie. Bd. I. iv. Hilgender and Paulicki in Centralblatt für die medicinischen Wissenschaften, 1869, No. 47. bacillus subcutaneously or into the mucous membrane of the trachea of a guinea-pig is somewhat as follows:-at the place of inoculation there is rapidly formed a fibrinous exudation, and death follows about the second or third day. The post-mortem characters are hæmorrhages and inflammatory points in the muscular structure, capillary extravasations and bleeding in the internal organs, swelling of the glands and of the spleen. The specific bacilli are confined to the affected mucous membrane or to the seat of inoculation. Loeffler summarises the results of his experiments on guineapigs in the following words :-"The facts illustrate in a convincing way, that the death of the animal was not caused by a spread of the organism generally throughout the body, but through a different kind of action developing locally. The hæmorrhagic oedema, the fluid in the pleura, the lobular brown consolidation of the lungs, which, without the presence of bacilli, develop in these organs, definitely prove that a poison produced at the seat of infection circulated through the blood stream, which was capable of causing profound changes in the walls of the vessels." Very instructive were also the experiments of Loeffler on inoculations of the vagina of young guinea-pigs. The vagina of the guinea-pig is closed by a fold of skin; a disturbance of this fold causes a superficial, and to the naked eye, invisible erosion of the epithelium, yet this is a sufficient lesion for the penetration of the bacillus and the production of a fatal diphtheritic vaginitis. With old guinea-pigs the epithelial layer is thicker, and a great proportion of such experiments fail. Reverting now to the observations of Loeffler on the pathological appearances in the human subject, a typical case may be quoted. In a boy five years old who died of true diphtheria on the seventh day of the disease, the post-mortem appearances were as follows: pseudomembrane in the throat, larynx and trachea, hæmorrhagic broncho-pneumonia. No noticeable change in the other organs. Sections were made of the uvula, tonsils, lungs and spleen. The extreme tip of the uvula was destitute of epithelium, in place of which it was covered by a closely adherent broad pseudo-membrane. In the most superficial layer of this were numerous micrococci and rods, beneath this was a layer with many nuclei, then followed the typical bacilli; where these ceased, the |