In eight out of ten occupations associated with exposure to coal gas, tar, pitch or soot the incidence of cancer of the bladder is greater than that found in the general male population, and in five of the ten it is from one and a half to four times as great. Three of these occupations show the highest figures for incidence of cancer of the bladder observed among the forty-six occupations investigated. Various possible sources of error in these figures are discussed, of which the most serious is the smallness of the numbers of deaths involved. The corresponding data for cancer of the prostate give less consistent indications of an occupational liability. The subject needs much further enquiry, but it has seemed best to publish now, without further delay, such material as is available, rather than wait for another long term of years while more data accumulate.

A large, and quite essential, part of this investigation, namely the computing of the population for each occupation recorded on the death certificates, and the calculation of the ratios, has been carried out by members of the staff of the Registrar General, to whom we wish to express our great indebtedness. We have to thank the British Empire Cancer Campaign for a grant which enabled the special enquiry into individual cases to be made, and to record our gratitude to those who assisted so willingly in carrying out this enquiry.

1. By means of the Old Standard bismuth sulphite medium B. typhosus was cultivated 44 times out of 50 examinations of the stools of 50 typhoid fever patients and convalescents.

2. By means of the same medium B. paratyphosus B was cultivated 22 times out of 27 examinations of the stools of 27 different cases of paratyphoid fever.

3. In 13 examinations of Belfast sewage in different months during 1928 and 1929, by means of the Old Standard sulphite media, B. typhosus was isolated on 10 occasions. In two examinations of Lisburn sewage B. typhosus was isolated. Although no special search for B. paratyphosus B was undertaken, this organism was isolated on two occasions from Belfast sewage. The viability of B. typhosus and B. paratyphosus B in sewage is longer than was suggested by the work of previous observers. It has been possible to cultivate B. typhosus and B. paratyphosus B from the deposit of sewage stored in a bottle at room temperature for 3 weeks. On one occasion B. typhosus was found alive at the end of 5 weeks.

4. On two occasions water from the River Lagan was examined, and on one of these B. typhosus and B. paratyphosus B were cultivated.

5. For the isolation of the B. enteritidis Gaertner the media gave good results in the examination of faeces from cases of food-poisoning.

Epidemic encephalitis made its appearance in Glasgow in 1918, although it was only in 1919 that its prevalence was such as to lead to its recognition. It recurred annually till 1924, and, during this period, the change in the clinical features from year to year suggested that it had passed through an evolutionary phase. While ocular symptoms were probably the features most common to all epidemics, prolonged lethargy and somnolence characterised the earlier cases; choreiform and myoclonic movements were more prevalent in 1920 and in 1921, while in 1924 there appeared for the first time a considerable proportion of cases with spinal signs and symptoms, which simulated acute attacks of insular sclerosis.

1. A technique for comparing the spermicidal powers of pure substances is described in detail. It is hoped that this may be accepted as the standard technique for the purpose.

2. The killing concentration of each substance is determined by this technique. The killing concentration is defined as the lowest concentration, in the series 2, 1, ½, ¼ per cent., etc., which suffices to kill every guinea-pig sperm suspended in glucose-saline solution in half an hour at the temperature of the body in four consecutive experiments, the majority of the control sperms being moderately or very active.

3. 36 substances have been graded by this technique.

4. Mercuric chloride and formaldehyde were found to be the most spermicidal substances. The killing concentration of each per cent.

5. Hexyl resorcin kills at per cent., soaps at per cent.

6. Formaldehyde and hexyl resorcin, among other substances, seem likely to be useful as contraceptives.

7. The significance of the high spermicidal power of soaps is discussed.

8. Quinine bisulphate and chinosol, which are perhaps more commonly used as contraceptives than any other substances, only kill at ½ per cent.

9. Certain very poisonous substances have very slight spermicidal powers. This applies to potassium cyanide, prussic acid and strychnine hydrochloride.

10. Foaming mixtures, consisting of acids and sodium bicarbonate, could probably be used alone as contraceptives.

11. The acrosome is the part of the sperm most vulnerable to spermicides. It tends to swell up and burst.

12. Sperms are very susceptible to changes in osmotic pressure.

13. It is the hydrogen ions and not the anions of acids that kill sperms.

14. The suggestion that tribasic acids would be found to be more spermicidal than dibasic, and dibasic than monobasic, is not substantiated.

15. Substances which reduce surface tension are often effective spermicides.

16. The characters of the ideal chemical contraceptive are discussed.

17. The need for co-operation in research in chemical contraception is stressed.

1. Sera from 500 patients, mostly natives of East Africa, were tested by the Kahn and Wassermann tests, under conditions described.

2. Clinical data were available in the case of 448 specimens. The results of tests upon 230 sera from cases believed to be yaws and syphilis and 218 cases believed not to be yaws and syphilis are discussed. In 46 of the 230 cases, treatment had previously been given.

3. In interpreting results, the resolutions of the League of Nations' Conference on the Serodiagnosis of Syphilis were strictly followed.

4. In the performance of the tests recognised standard methods were used.

5. The two tests correlated exactly in 96·4 per cent. of all cases.

6. The Kahn test was the more sensitive to yaws and syphilis.

7. The Wassermann test alone gave one non-specific reaction.

8. The reagents used in the Kahn test did not deteriorate when kept for two months at room temperature.

9. It is suggested that although the use of both tests is preferable when practicable, the Kahn test alone is a reliable diagnostic measure in the tropics.

1. Fletcher and Lesslar's observations on two serological types of tropical typhus have been fully confirmed.

2. The antigenic relationship between the indologenic B. proteus X 19 and the non-indologenic Kingsbury strain is of the same order as that obtaining between the X 19 and X 2 types of B. proteus X.

3. The Kingsbury strain is an antigenic variant derived from the original X 19 culture and represents another serological type of B. proteus X. The symbol XK is suggested for this type.

4. Sera from cases of classical European typhus and of endemic typhus of the United States of America and of Australia have been tested for the occurrence of main and group O agglutinins for the known types of B. proteus X.

5. H agglutination as source of error in the diagnosis of typhus cases is illustrated by some examples.

6. Sera from cases of tsutsugamushi from Sumatra and Japan react with type XK like the Malayan cases of this disease described by Fletcher and co-workers.

7. This latter reaction is of the order of group O agglutination. It is suggested that antigenically the virus of tsutsugamushi corresponds to another serological type of B. proteus X which is yet unknown.

8. The data published on the serum reactions in Rocky Mountain spotted fever and in the “fièvre exanthématique” of Marseilles are analysed. It is suggested that these two diseases represent further serological varieties of typhus.

9. The significance hitherto attached to negative agglutination tests with B. proteus X and to negative cross-immunity tests obtained with some typhuslike diseases requires revision in the light of recent observations.

1. The tissue reactions in rabbits from intravenous injections of live and dead Staphylococcus aureus and massive doses of indian ink and colloidal silver have been studied.

2. Any particles injected into the circulation cause the accumulation of polymorphs in the lung capillaries.

3. Inert colloidal particles such as indian ink are clumped in the capillaries of the lungs, liver, spleen and kidneys, and are phagocytosed by the endothelial cells.

4. Staphylococci (S. aureus), live or dead, are nearly all held up in the lungs, where they are actively phagocytosed by the polymorphs within 5 minutes of an intravenous injection.

5. Subsequently the cocci are distributed to the other organs, where phagocytosis continues mainly by polymorphs, but in the liver also by the Kupfer cells.

6. Special attention is drawn to the localisation of the cocci in certain areas in the kidneys.

7. Platelet counting on animals injected with various substances showed that there is an agglomeration of the particles with the platelets, which are consequently removed from the circulation.

8. In the case of the inert particles the platelets are then restored to the circulation. With organisms (S. aureus) some of the platelets appear to be completely removed from the blood together with the bacteria.

In several previous reports we have described the behaviour of communities of mice, submitted over long periods of time to the risks attendant on the epidemic prevalence of a bacterial infection. These communities have been recruited in ways varying both as regards the rate of immigration and the nature of the immigrants.