The experience of the last few years in the Westphalian coal-field has shewn that the presence of Ankylostoma in a mine may become a matter of considerable industrial importance. Since it has been shewn that several of the metalliferous mines in Cornwall are throughly infected, the question of how far it may be present in, or spread to, other British mines has arisen in a practical form. When any large number of individuals have to undergo a medical examination for any such purpose it is of importance that such examination should be convenient at once for the examiner and for the examinee, that it should occupy as short a time as possible, and should, at the same time, be reliable. The diagnosis of the presence of Ankylostoma is commonly made by searching for the characteristic eggs in the faeces; and indeed a final diagnosis must rest in nearly every case on the results of this procedure. Which is therefore not easily replaced by any other method when separate individuals are in question. But as applied to a large body of active working men this process has many disadvantages, and at the request of the Home Secretary an inquiry has been made into the practicability of other methods of examination1.

1. Dried tubercle bacilli extracted with hot solutions of spirit, alcohol, alcohol-ether, Aronson's mixture, yield large percentages of fatty substances.

2. On filtering the boiling extracts a white acid-fast precipitate deposits on cooling.

3. The filtrates on evaporation can be saponified by soda, and on subsequent agitation with ether and water two extracts can be obtained —an ethereal and a watery extract.

4. The ethereal extract contains fat which is not acid-fast.

5. By saponifying the dried ethereal extract with alcoholic potash and decomposing the resulting soaps with sulphuric acid a mixture of fatty acids is obtained containing probably oleic, isocetinic and myristinic acids. None of these are acid-fast.

6. The watery extract (soap) on decomposition yielded a fatty acid with a melting point corresponding to lauric acid.

7. The filtrates also yield lipochromes to which the cultures of tubercle bacillus owe their colour.

8. The white acid-fast precipitate obtained by the original extraction can be saponified, but with great difficulty.

9. By prolonged boiling with alcoholic potash the acid-fast precipitate is decomposed and results in the deposition of an acid-fast snow-white flaky powder, and a non-acid-fast filtrate of fatty acids.

10. The chemical examination of the white flaky powder shows it to be an alcohol.

11. Acid- and alcohol-fastness of the tubercle bacillus is due to the presence of an alcohol.

The effects produced upon bacteria by environmental conditions constitute factors which until recently have been studied with but too little regard to scientific accuracy, even by the bacteriologist investigating the conditions under which pathogenic bacteria occur in nature, and whilst probably leading a saprophytic existence.

Several causes have contributed to bring the problems of infantile mortality into greater prominence during recent years. The increased interest in child-study, the growth of humanitarian feeling, and the rapid decline of the English birth-rate during a period of Imperialist expansion have combined to set a higher value upon infant life. In this connection less is heard of the “survival of the fittest” and the “devastating torrent of babies”; the fear of over-population which induced many to regard a high rate of infantile mortality with complacency has faded before the danger of depopulation, and the so-called doctrines of Malthus have given place to the gospel of Fecundity. To those engaged in the work of preventive medicine the continuance of a high rate of infantile mortality in spite of the great improvements in public health administration of the last thirty years is a problem of special interest. The following table shows that although the general death-rate has steadily declined since the early seventies there has been no corresponding decline in infantile mortality, which in fact has increased during 1886–1901. The comparatively low rates in 1902–3 are explained by the exceptional meteorological conditions prevailing during the summer months:—

Hay Fever is a disease which on account of its peculiar interest has attracted the attention of the medical world ever since it was first accurately described by Bostock of London in 1819. To what extent the disease occurred before his time is difficult to determine; but from the fact that his observations were at once confirmed by a number of contemporary medical men it is probable that at the time of his writing it was not very uncommon. We have no exact knowledge of the existence of the disease in England prior to the nineteenth century, and indeed many authors hold that the chief etiological factors were not present in earlier times. It is my purpose in this paper to discuss the researches recently carried out by Prof. Dunbar at the State Institute of Public Health in Hamburg, which have very considerably increased our knowledge of the interesting malady, and have also narrowed the field for its future investigation.

One of the most striking points in the pathology of Bacterial Dysentery is the fact that while the bacilli are found regularly in the mesenteric glands, they are not found in the spleen or other organs, and do not occur in the blood, urine, or milk. In this respect Lentz (p. 320) points out that the disease differs markedly from the septicaemic diseases, such as typhoid, and that it must be regarded as a local infection of the intestinal mucous membrane and corresponding lymphatic glands by the bacillus, the toxin alone passing into the circulation and giving rise to the typical clinical picture, which, as in the case of cholera, gives the impression of a severe poisoning or toxaemia.

The conclusions I seek to draw from this part of my investigations are:—

1. That a malarial form of horse-sickness probably occurs naturally.

2. That when animals which are either naturally relatively susceptible, such as the donkey, ox, and goat, or animals which have acquired protection, e.g. “salted” horses, are inoculated with virulent horse-sickness blood, their blood conveys a modified infection of horse-sickness which is malarial in type.

3. That this malarial from is associated with the presence of parasites within the red corpuscles of the blood of the infected animal.

4. That the blood of “salted” horse which have been previously regularly inoculated during several months is of a dangerous order of virulence. Vide former experiments.

5. That the blood of “salted” horses which have only been once inoculated after several months' rest conveys a fairly severe fever.

6. That the blood of “salted” horses, which have not been inoculated for even a year, can still convey infection.

7. That “unsalted” horses which have been inoculated a year previously with “salted” blood convey only a week infection.

8. That a severe attack of malarial horse-sickness gives a considerable degree of protection against subsequent inoculation with “salted” blood.

9. That when regularly inoculated “salted” horses are used to produce blood giving severe fever, such fever may become so severe as to cause death with symptoms of horse-sickness.

10. That the blood of the latter animals which die can produce virulent horse-sickness in clean horses, if used in a considerable dose, i.e. 20 c.c.

The following paper embodies the main facts obtained during a prolonged investigation as regards the pollution of Tidal Waters and of Shell Fish, undertaken on behalf of the Royal Commission on Sewage Disposal.

Dysentery is, with the exception of Malaria, the disease most prevalent in Ceylon, and the mortality caused by it surpasses by far that due to any other cause. From the reports of Dr Perry, P.C.M.O. of the Colony, one sees that the total number of cases treated in all hospitals during the year 1902 was 3,017, with 999 deaths. In 1901 the number of cases was 4,177, with 1,543 deaths. The deaths due to Malaria were only 115 in 1902, and 89 in 1901; the deaths caused by Enteric Fever were 63 in 1902, and 74 in 1901.

Futher experience with the method of measuring the precipitum obtained when experimenting with precipitating antisera has shown that finer degrees of reaction cannot be satisfactorily determined by means of the apparatus described by Nuttall. In the latter apparatus capillary tubes were used in which to measure the precipitum therein deposited. It is true that capillaries as far as possible of the same calibre were used, nevertheless we have found that different readings were obtained when experimenting with tubes of varying calibre, variations evidently due to physical causes which prevent an equal degree of “packing” of the deposit in tubes of unequal width. We have modified the method after finding that calibrated tubes of uniform bore gave more constant results, and have devised a simple apparatus which greatly facilitates the making of measurements.

By means of the graphic records given on Plates II–VI and VIII the following facts have been illustrated.

Immunity to Erythrocytes.

Normal rabbit's serum is relatively innocuous for bullock's erythrocytes. The serum of an immunised rabbit acquires the power to dissolve bullock's erythrocytes.

Besides acquiring the power to dissolve bullock's erythrocytes, an immune serum may also acquire power to clump them, and it has been shown that the phenomena of haemolysis and of agglutination are independent.

The powers acquired by the immune serum can be artificially modified. The serum may be deprived of its powers by heat. Serum cautiously so deprived of its haemolytic power can have it restored by the addition of normal serum. The haemolytic power of the un-heated serum is augmented if normal serum be superadded.

It has been shown that an immune serum only differs from a normal serum by its containing antitoxic bodies which are endowed with powers of specific reaction with the bullock's erythrocytes.

The mechanism by which erythrocytes are laked by an immune serum has been analysed, and it has been shown that the solution of the erythrocytes is effected through the intervention of an anti-erythrocytic body called forth by immunisation. The erythrocytes which have been subjected to the action of this product of immunity give indication of their reaction with it if they are subsequently or concomitantly placed under the influence of normal serum. The erythrocytes and normal serum together, therefore, form a combined indicator of the presence of the anti-eiythrocytic body. The part played by normal serum has nothing to do with the acquisition of immunity.

The only conclusion drawn from the above observations is that in the production of immunity to erythrocytes the serum of the immunised animal acquires certain powers which are concomitant with, but are not necessarily the cause of the immunity. This special case of immunity to erythrocytes is therefore probably parallel to induced immunity to those bacterial toxines for which antitoxines are known to exist.

The course and progressive augmentation of artificial immunity to erythrocytes has also been illustrated, and it has been shown that erythrocytes saturated with anti-erythrocytic body retain the power to augment the immunity of an already immune animal.

The serum of an animal actively immunised has power to confer passive immunity upon other animals, and the course of this passive immunity differs in the two cases when it is induced in the same species and in a species alien to that providing the immune serum.

The experiments with bullock's erythrocytes have been repeated in parallel observations with ricin in order to permit of the observations on haemolysis being utilised in drawing conclusions on the behaviour of bacterial toxines.

By adjusting the conditions of experiment in such a way that the minimal lethal dose for an animal was also the minimal agglutinating dose in test-tube experiments, it has been possible to give graphic records showing the parallelism between the processes when erythrocytes or living animals are used as indicators of the presence of free ricin. In this way it has been possible to illustrate the determination of the minimal lethal and minimal agglutinating doses of ricin and that quantity of antitoxine (antiricin) which is necessary to abolish the corresponding actions in the animal and in the test-tube, and to show that the mixture of toxine and antitoxine which is physiologically neutral in vitro is also physiologically neutral in vivo within the limitations imposed by the preliminary determinations.

The consequences of conferring passive immunity upon the guinea-pig by means of active immune serum of the rabbit have also been illustrated, and it has been shown that the alien antiricin serum leads to the production of agencies directed against itself.

Ricin neutralised by antiricin retains its power to produce immunity when injected into the species of animal which has yielded the antiricin.

In connection with the conference of immunity to erythrocytes and to ricin, the nature of the difference between normal and immune sera has been studied. Attention has been directed to the possession by normal sera of properties which simulate those possessed in more marked degree by the immune sera. In the case of haemolysis, it has not been possible to clearly demonstrate that the actions manifested by the normal and immune sera are distinct, although the weight of evidence is in favour of this view. In the case of ricin, however, it has been possible to demonstrate that the immune serum possesses properties which are quite distinct from those possessed by normal serum, and that the latter does not interfere with the action of ricin because of the natural presence of a trace of antiricin. In the case of immunity to ricin, the antitoxine is certainly something which has been super-added to the serum in consequence of the process of immunisation.

The facts ascertained in regard to artificial immunity to erythrocytes and to ricin completely agree. Only in oue point is it impossible to be quite sure that the phenomena are identical, viz., in the simulation by normal serum of the powers characteristic of the immune serum; for the demonstration that the two are distinct has been possible for ricin, but open to doubt in the case of erythrocytes. My investigations have been extended to diphtheria and tetanus toxines and to cobra venom, kindly placed at my disposal by Sir Thomas R. Fraser. They have however been interrupted, but so far as they go they support fully the observations made on ricin and erythrocytes.

For a considerable number of years, Belfast has suffered from a high typhoid fever death-rate, and the investigations embodied in the following pages were undertaken at the request of the Corporation, with the purpose of determining the sanitary measures required to prevent, as far as possible, the occurence of typhoid fever in the city.

It will perhaps be generally admitted that few of the practical problems which have from time to be faced by the Medical Officer of Health in his capacity of statistician present more difficulty than is often involved by the estimation of populations. This problem may be said naturally to present itself in three different forms, according as the estimate is required for a past, a present, or a future date. Practically, however, there are but two primary divisions of the problem, the one relating to dates since which a census has been taken (and its results published), and the other to dates subsequent to that of the last published census. This distinction is pointed out by Dr Cressy Wilbur in the “Thirty-second Annual Report (for 1898) on the Vital Statistics of the State of Michigan.” He there refers to the first class of cases as estimates of inter-censal, and the second as estimates of post-censal populations.

The object of the Swedish Antarctic Expedition was to conduct researches relating to the geography and natural history of the Antarctic regions south of Cape Horn. The expedition was to start from Sweden during the autumn of 1901. On the approach of the Antarctic winter, in February or March 1902, some of the party were to be landed in a suitable place in the Antarctic regions, with the object of wintering there. The members remaining on board the ship “Antarctic,” were to carry on investigations in the regions around Cape Horn, the Falkland Islands and South Georgia. The next summer, i.e. in December 1902 or January 1903, the ship was to return in order to pick up the wintering party at their station; and, thus reunited, the whole expedition was to go back to Sweden, where, as we had calculated, we should arrive in the spring of 1903.

In a recent Report (1) upon the new parasitic bodies associated with tropical splenomegaly, Lieut. S. R. Christophers, I.M.S., published a method of producing chromatin staining in sections. This method, however, labours under the disadvantage that, after staining, the section must be dried in the air before it is cleared and mounted, since the chromatin reaction is lost if dehydration by absolute alcohol is attempted. The consequent shrinkage of the tissue, even in very thin sections, renders the method of little service for delicate work.

In a previous paper (Volume III., p. 95 of this Journal) we gave an account of our observations on cases of ankylostomiasis in Cornish mines. The present paper will be devoted to a more general discussion of the disease from the point of view of its prevention, particularly in mines.

Finally, I must express my hearty thanks to the many medical men and others who have given me aid and hospitality in my wanderings after the truth about beriberi. I must mention particularly Dr Giddy and Captain Vincent on Christmas Island, Drs Ellis, Leask and Murray Robertson in Singapore, Drs Travers, Gimlette, Watson, McClosky and Mr Galloway in Selangor, and Drs M. J. Wright and Connolly in Perak, and Messrs Mason, Ponsford, Sanderson, and Hembrey in Pahang, without whose aid and kindness I could have seen but little. I must also thank my friend Dr G. S. Buchanan, Secretary of the Royal Commission on Arsenical Poisoning, for forwarding me much information.

It would seem from my observations that certain of the current theories of the causation of beriberi will not account for the conditions which have been encountered by me. The dietetic or physiological, the unsound food, the arsenical, and the emanation theories all appear to be insufficiently in accordance with the attendant circumstances to have accounted for the spread of the disease.

It is suggested that certain articles of diet, by virtue especially of containing phosphorised and fatty matters, may tend to ward off the disease when given in sufficient amounts. So far as there was any semblance of a positive result in the observations it is suggestive that beriberi is communicated from person to person more or less directly or through fomites as an actual infection. This infection is not of the nature of a septicaemia (since the internal organs at death prove sterile), but to a surface condition about the upper air passages. From the observation of the throats of a number of patients it is surmised that the redness which is therein seen, especially in early cases, may be intimately connected with the disease. The appearances and disappearances of beriberi and the more or less seasonal waves of prevalence of the disease are not unlike those which are seen in the case of the infective diseases which we meet with in this country. The proneness of the newcomer to suffer fits in also with such a view. The difficulty in tracing out the source of infection in a disease like diphtheria is often great, especially since we know that the causative organism may be carried by unsuspected refractory of immune persons or animals.

With considerations such as these it is held by the writer that there is no inherent impossibility in explaining many of the circumstances connected with the spread of beriberi.

Observed facts seem to show that beriberi should rather be considered in the light of a “gang” or “institutional” disease than as a “place” or “house” disease.

On visiting a farm near Grahamstown for the purpose of examining some cattle, our attention was drawn to a young dog which was sick. The owner stated that he had been unable to keep a dog on the place, that they all died.