In the course of investigations into outbreaks of typhoid in the county for which I act as Medical Officer, I have discovered a number of typhoid carriers whose histories seem worth placing on record as showing the extent to which the endemicity of the disease in rural areas is maintained by carriers. Of twenty-two found, four were identified in 1908, two in 1910, three in 1911, one in 1916, one in 1917, five in 1918, and six in 1919. Five were men and seventeen were women, giving a proportion of 77·3 per cent. of female carriers. Of the chronic typhoid carriers found by the German stations up to the close of 1907, 82 per cent. were women. All of my carriers were intestinal, one being a urinary carrier as well. As in every case attention was directed to the carriers owing to a case or cases of actual typhoid fever occurring; this experience indicates that, as is generally believed, faecal carriers are altogether in excess of urinary carriers, or that urinary carriers may not have the special malignancy commonly attributed to them.

There are so many unexplained problems in connection with food poisoning that it is still of importance to study in detail and with care every outbreak. I have perused the records of several hundred food poisoning outbreaks, published and unpublished, and the prevailing impression left is one of regret that so many opportunities of clearing up obscurities and elucidating channels of infection have been lost by omission to push investigations home. The outbreak recorded here is in pleasant contrast and worthy of detailed study. It is noteworthy for two features. The bacillus isolated was not only isolated from the incriminated food but it was recovered from water from a tank in the slaughter-house, a rather unusual feature. This suggests a method of infection which has not hitherto been reported.

In recent studies on experimental epidemiology, and especially in a series of reports by Webster (1922, 1923 a, b, c, d, e, f and g), attempts have been made to standardise certain of the factors concerned in the spread of bacterial infection among mice. One such factor is dosage, to which great importance has been attached by Amo⋅s (1922 a and b) and also, though to a somewhat less extent, by Webster, whose later work leads him to emphasise the importance of host-susceptibility in determining the form of the epidemic wave. Webster would appear to regard variations in dosage as decisive, in the sense that an effective dose must be applied; but once the critical limit of dosage is exceeded he would give first place to host-susceptibility in determining the subsequent course of events.

1. Certain cross-immunisation experiments (on monkeys) with B. abortus and B. melitensis carried out in 1921 were repeated with the same effective result.

2. It was found that goats vaccinated intravenously with B. abortus in massive doses are protected from subsequent infection with a virulent B. melitensis strain, and fail to pass that organism in the milk.

3. The record of the effect of B. abortus vaccine in treating three cases of undulant fever is given.

In conclusion I wish to express my thanks and gratitude to the staff of the Lister Institute for the hospitality of the laboratories and for many valuable criticisms.

In the preceding report (Topley and Ayrton, 1923 a) we have described a technique by which measurements may be obtained of the excretion of B. enteritidis (aertrycke)1 in the faeces of mice.

1. The lesions produced by the different dusts employed in these experiments, and the conclusions to be derived thereform, have already been discussed in Section 6 of this paper (see p. 455, et seq.).

2. Plaque formation has been discussed. Evidence has been produced to show that the large plaques which tend to be formed in the parenchyma represent permanent pulmonary lesions. Small plaques, on the other hand, may be formed within the pulmonary lymphatics, in which case they may disintegrate in course of time. Such plaques have been termed “intralymphatic plaques.”

3. Evidence has been brought forward against the view that the degree of harmfulness of a dust is proportionate to the degree of angularity and sharpness of its consituent particles. Nor has the supposition that the dusts which stimulated phagocytosis were those which contained organic matter been confirmed experimentally. Although silica may be regarded as a cellpoison and that this may account for the inability of the phagocytes to remove it, there are probably other factors than this, since shale—universally admitted to be one of the least harmful dusts—contains from 55 per cent. to 60 per cent. of silica. As to why one dust is harmful, and another not, is a problem as yet unsolved.

4. The origin of the dust-cells has been studied. Reasons have been given to justify the belief that dust-cells are frequently derived from the alveolar epithelium. This, however, does not exclude the possibility of some participation of leucocytes or endothelial cells in the phagocytosis of dust particles.

5. The chief modes of elimination of dust from the lungs have been discussed. It has been shown that the dusts which stimulate phagocytosis tend to be eliminated from the lung by both bronchi and lymphatics, while such elimination as occurs of the dusts which elicit but a feeble phagocytic response is through the lymphatics rather than the bronchi.

In January, 1923, a small outbreak of dysentery occurred amongst the nursing staff of a certain institution. In all there were six cases. Only one case, the first which occurred, showed symptoms of any great severity. In the remaining five cases the symptoms were slight, and the patients were able to return to duty m seven or eight days from the commencement of the illness.

Conditions in institutions for children or defectives may become peculiarly favourable to the propagation of hookworm disease. The subject of the present study is a long-standing infection with Ancylostoma duodenale in the Hospital for the Insane at Goodna, Queensland, the largest of the three hospitals for the insane maintained by the State Government. The investigation was of special interest because the institution is in a region in which the general population is free from hookworm disease, owing to low rainfall, and because the infection was with A. duodenale, while the predominating hookworm infection of Queensland is with Necator americanus.

In a paper on Bacillus coli infections of the urinary tract, Dudgeon, Wordley and Bawtree (1922) refer to two cases of acute pyelo-cystitis, one of which terminated fatally, due to slow lactose fermenting bacilli which were strongly haemolytic. The diagnosis of paratyphoid fever was considered probable on clinical evidence, chiefly because of the severity of the illness and the prolonged pyrexia which was infinitely longer than occurs in typical cases of acute coli fever. An organism was isolated from each case with identical cultural, serological, and haemolytic properties. On cultural evidence both strains were distinct from true colon bacilli, as they formed blue colonies on litmus-lactose-agar which were similar in appearance to typhoid-paratyphoid colonies, and slowly fermented lactose-broth.

In a preceding paper1, details were given of an investigation which demonstrated that an epidemic of milk-borne enteritis occurring in Aberdeen in 1919 was due to infection of milk with dysentery bacilli of the Flexner type. It was further stated that the epidemiological and clinical features of antecedent epidemics of milk-borne diarrhoea were such as to suggest that the former epidemics were probably also dysenteric infections, although bacteriological investigation had failed to identify the causative organisms.

The Standard Tetanus toxin sent out by the Hygienic Laboratory of the United States Public Health Service is in the form of a dry powder, and the required quantities have to be weighed out.

Pathologists and physiologists are agreed that the capillary endothelium is of high importance in the animal economy, though it is admitted that its functions are involved in much obscurity. With the immunologist, the primary difficulty is lack of physiological data which would enable him to start with the normal functions and to interpret abnormalities in the light of these. And it is obviously far from easy to plan experiments providing the sort of information the immunologist wants about the functions of endothelium as part of a living mechanism, in which parenchymatous cells, body fluids, and endothelial channels jointly participate.

The presence of antibodies in the body fluids of the offspring of immunised parents has long been studied and variously explained. In 1912, Famulener2 published a clear summary of the work upon the subject up to that date. Renewed interest in the problem has been aroused by the work of the Department of Animal Pathology of the Rockefeller Institute for Medical Research, where the transmission of immunity to the Bacillus abortus is being studied. It has been shown by Little and Orcutt3 that agglutinins for this bacillus are transferred exclusively by the colostrum, since a calf from which colostrum is withheld does not show this agglutinin in its serum, although a high titre of agglutinin may be demonstrable in both serum and colostrum of the dam. Later Orcutt and Howe4, using a method of separating the protein fractions of serum devised by the latter5, 6, showed that the appearance of agglutinins in the serum of a calf fed with colostrum of high agglutinin titre was closely related to the appearance of euglobulin, which is absent from the blood of the newly born calf. Further, Smith and Little7 showed that this absorption of agglutinin from the digestive tract also occurred when the calf was fed with serum rich in that antibody. The association of agglutinin with the globulin fraction of serum, and in particular with the euglobulin fraction, has been demonstrated by Orcutt and Howe4, who found that “the agglutinins are associated with the protein fractions which are precipitated up to and including 16·4 per cent. of sodium sulphate,” and that “a large proportion of the agglutinins is associated with the fraction which is precipitated by 14·2 per cent. of sodium sulphate, euglobulin.” Again, although a milk might show a high titre of agglutinin, with no corresponding increase in the proportion of its globulin, yet the agglutinin was removed from the milk by a concentration of sodium sulphate which removed the globulin fraction of the protein.

1. Evidence is given that there exists a multiplicity of serological groups of B. diphtheriae.

2. Ten of these groups have been studied in this communication.

3. Into these ten groups could be placed all except 16 of 348 strains of virulent B. diphtheriae investigated.

4. A description of the technical difficulties encountered is included in the hope that this may prove of service to other workers.

Some evidence on the antigenic structures of different strains is advanced.

5. The application of this method of investigation to the problems of epidemiology is briefly discussed, and evidence of its value brought forward.