Tetanus antitoxic horse sera were fractionated with sodium sulphate and by electrophoretic separation. The activity of the native serum and of fractions was determined in vivo in the mouse and guinea-pig and in vitro by the flocculation method. All the sera and fractions showed several zones of flocculation. The flocculation optimum corresponding to the toxin-antitoxin complex was selected by absorption of antitoxin to the floccules. The distribution of activity amongst the electrophoretic components of the native serum was computed from electrophoretic analysis, refractive increment measurements and assays of the activity of the electrophoretically pure fractions.

In all the sera examined the antitoxin was associated with both β- and γ-globulin. The γ-globulin antitoxin had a shorter flocculation time and a higher in vivo/in vitro ratio than β-globulin. The in vivo/in vitro ratio of γ-globulin was two to three times that of β-globulin antitoxin, its exact value depending on the toxin concentration against which the antitoxin was measured. The avidity of γ-globulin antitoxin was greater than that of β-globulin antitoxin judged by two independent ‘dilution’ tests, namely a comparison of the mouse unitage using two concentrations of toxin and a comparison of the values obtained with one concentration of toxin in the mouse and in the guinea-pig. The in vivo values of the various antitoxins varied with the toxin employed in the test.

During the first course of immunization in a horse the γ-globulin antitoxin rose to a constant value; β-globulin antitoxin increased to a still higher value later in the course. The avidity of the serum, as measured by the two ‘dilution’ ratios, also increased during immunization.

1. The haemolytic complement-fixation test and the conglutinating complement-absorption test, as well as the agglutination reaction and the antiglobulin sensitization test, have been used to study a change which occurs during egg adaptation of the Christie strain of R. burneti.

2. Antigens were prepared from yolk sacs of the third to the ninth passages inclusive. Irrespective of numbers of rickettsiae, antigens from the third and fourth passage failed to fix complement with homologous (human) antiserum, unless the latter was in very low dilution. From the fifth passage, however, antigens fixed complement with high dilutions of the same antiserum and thus resembled the classical Henzerling strain antigen.

3. Third-passage antigen failed to fix conglutinating as well as haemolytic complement with high serum dilutions. The agglutination reaction and antiglobulin test, however, showed that third-passage antigen absorbed antibody almost as well as ninth-passage and Henzerling strain antigens.

4. It was not possible to find out if the change in behaviour was due to a true antigenic variation or to non-specific hindrance of complement absorption. Heating failed to alter the behaviour of the antigens and the results of absorption tests were inconclusive.

A method for the estimation of chloramphenicol in faeces and bile is described. It has been shown that the bile contains high concentrations of the antibiotic, but the faeces small amounts. It is considered that the faecal concentration is dependent on the biliary supply.

The action of chloramphenicol on the gut flora is described and the dominance of yeasts on complete suppression of the conforms is reported, drawing attention to the possibility of intestinal moniliasis following unrestricted use of the antibiotic.

An explanation of ‘relapses’ in the chloramphenicol treatment of typhoid fever is given, and the possible effect of chloramphenicol on immunity response is discussed.

The results of an investigation into the incidence of canicola fever amongst owners of dogs infected with L. canicola is described.

Visits were made to forty-six households in which infected dogs lived. Altogether 137 household contacts were examined and blood samples from 99 or 72·3 % were tested for agglutination against L. canicola. All the sera proved negative.

A detailed classification of the kinds and conditions of housing and of householders is given.

Some of the difficulties in explaining the relationship between the disease in dogs and man are discussed; the results of the present survey and the experience with some reported cases of human canicola fever show that there is great variation in the risk of infection to owners and others hving in the same house with diseased dogs.

Some other source of infection common to man and dog is possible.

It is recommended that in the light of present knowledge greater attention should be paid to the preventive aspect and that more propaganda should be directed to make dog owners aware of the possibilities of infection and of the importance of observing hygienic principles when handling dogs and particularly when dealing with dejecta.

It has been shown that the cells in exudates produced by the injection of tuberculin into the serous cavities of sensitized animals are alive and not dead as claimed previously. Such cells consumed oxygen and glucose at the same rate as cells obtained similarly from normal animals but moved somewhat less actively. Purified tuberculin had no specific effect on the respiration in vitro of macrophages or neutrophil leucocytes derived from sensitized animals.

In a previous communication on the bacteriology of dehydrated fish (Shewan, 1945), data were presented concerning various aspects of the drying process, and their bearing upon commercial production was discussed. This communication reports further work, done mainly during the war, on the effect of storage conditions on the bacterial flora of various kinds of dehydrated fish products.

Experiments to determine the role of particle size in the infectivity of anthrax spores are described. Clouds of homogeneous particles were produced. The mortality-dosage curves for guinea-pigs and monkeys are given for clouds of various particle sizes. Data are given on the effect of time in the concentration-time relationship. The results are compared with those recorded by other workers on the relationship of particle size to respiratory retention.

Infectivity was highest with single-spore clouds, falling off as particle size increased. Reasons are given for attributing this effect to difference in site of deposition of different-sized particles.

The distribution of inhaled bacterial aerosols has been studied in guinea-pigs, monkeys and mice, using Bacillus subtilis spores labelled with radiophosphorus. Particle sizes from about 1 to 12μ have been used.

The guinea-pig shows the expected change of distribution with particle size; the proportion retained in the head increases with increased particle size. The figures correspond closely with those for man. Monkeys show similar results but are more irregular.

The subsequent fate of the retained particles has been studied and accords with what is known about ciliary removal.

The work is intended to link with parallel investigations of respiratory infection in closely similar conditions, and its implications are discussed in a paper on that subject (Druett et al. 1953).

The majority of sedentary lightly clad acclimatized European men and women in Singapore are reasonably comfortable in relation to their indoor thermal environment provided the effective temperature does not exceed 78° F. or fall below 73° F.

European women, who were, however, older as a group than the other subjects, preferred rather cooler conditions than European men or Asian men and women.

There were considerable variations between individuals in their comfort tolerance for various levels of warmth, but the average opinion of one individual was usually consistent provided sufficient votes were collected to provide an adequate sample at each level of warmth.

When the dry-bulb temperature was above 83° F., increasing the average air movement from a still to a more turbulent condition added to the comfort of the majority of European men and women. When the temperature was below 83° F. for men and 81° F. for women, moderately good air movement was rather less comfortable than slight air movement; whereas below 77° F. still air was more comfortable than slight or moderate air movement. Increasing the air movement within a compartment can thus be used for combating thermal discomfort only within a limited range of warmth, but within that range it is extremely useful.

Two groups of naval ratings who had been living in a warship in a tropical climate were reasonably comfortable at similar levels of warmth to the men in Singapore, but they were less tolerant of levels of warmth above the comfort zone.

1. Antibody occurs in the uterus and can be withdrawn by irrigation. Intrauterine antibody results from the introduction of antibody into the lumen of the uterus.

2. Neither free antibody nor the sensitization of the uterus has been produced by intramuscular injection of antigen, even when antibody has circulated in the bloodstream for periods from a few weeks to many months.

3. Active sensitization of the uterus follows upon the repeated introduction of antigen into the uterus.

4. It is concluded that antibody can be produced locally by some of the cells in the uterus when T. foetus antigen is present.

5. The uterus of the cow can be sensitized passively in vivo by the instillation of bovine anti-trichomonas serum so that the instillation 6–10 days later of Trichomonas antigen will produce the characteristic local anaphylactic reaction.

A description is given of the topography, type of farming carried out, and the living conditions of the agricultural community of a district in South Wales where a survey was made of the infection rate of rats with Leptospira icterohaemorrhagiae.

Leptospires were seen in stained sections of the kidneys of eighty-two of the 357 rats examined (23%). With a single exception, all the infected rats were adult, but no difference in sex-incidence was found.

Weil's disease occurs in this area, but no cases in man or cattle had been reported from this particular locality. Blood samples taken from six persons living on two heavily infested farms contained no anti-leptospiral agglutinins.