1. Experiments in laboratory animals are described, which were made to determine the specific antibody production following injections of diphtheria and pertussis antigens separately or in combination.

2. Agglutinins to H. pertussis vaccine were not increased or otherwise changed by combining H. pertussis vaccines with either diphtheria anatoxine or A.P.T.

3. A striking enhancement of diphtheria antitoxin production occurred when diphtheria prophylactics were used combined with pertussis vaccine. Such improvement in antitoxin production was most marked in the case of diphtheria anatoxine, but was also shown following the use of A.P.T. in combination with pertussis vaccine.

4. Diphtheria anatoxine combined with H. pertussis vaccine gave no better antitoxin response than did a.p.t. alone.

This paper records the results of systematic pneumococcus typing over a 7-year period in children from 4 days to 12 years of age in the R.H.S.C., Glasgow. Strains typed include those from respiratory tract lesions, from pus in middle ears, meninges, joints, serous sacs and miscellaneous purulent foci. A series of strains from normal throats serves for comparison.

The constant prevalence year by year of types 6, 19, 1 and 23 in all types of disease is striking. On dividing the cases into those under and over 2 years, the incidence of type 1 in the older children is four times that in the younger group. Conversely in those over 2 the incidence of the higher types (21–32) is only half that in the younger patients. No other significant difference in type distribution is observed on comparing the two age groups. Group IV pneumococci are commonly carried in the healthy nasopharynx, and are potential pathogens in young children in whom broncho pneumonia is generally an endogenous infection. There is evidence that the same type of pneumococcus frequently invades the entire respiratory tract and the middle ears. Only thirty of our cases were in the neonatal period and the apparent immunity of the newborn to the pneumococcus is discussed.

1. The participation times of a series of mixtures of horse serum and a pool of rabbit antihorse serum have been determined. The results have been presented in a table and isochrones drawn. Four distinct α procedure optima were found, suggesting that there may be at least four different antigen-antibody reactions concerned when horse serum reacts with a rabbit antihorse serum.

2. The reaction between horse serum crystalbumin and the same pooled rabbit antihorse serum has been investigated, and recorded-similarly.

3. Inhibition of precipitation was found to be more marked in the region of antigen excess than in the region of antiserum excess. Evidence is presented in support of the view that the occurrence of multiple zones may obscure this observation.

4. The results are compatible with the view that the second stage of the precipitation reaction is specific.

5. The isochrones correspond with Boyd's R type.

1. Standard Bact. coli cultures have been heated at 51° C. in phosphate buffered media having pH values ranging from 2·8 to 8·8, and survivor curves obtained.

2. Except at pH 3·9, the first continuous decline in viable numbers was followed by the establishment of a small fluctuating residual population which was apparently permanent.

3. The colony counts showed a moderate excess of unduly high values of x2, the bulk of which were encountered when the mortality was between 95 and 99·999%.

4. Prolonged incubation of the plates led to increased colony counts, but the rise was confined to the active disinfection phase. It occurred chiefly in the 95–99·999% mortality range and was moderate in degree. The x2 values were little affected.

5. The log survivors-time graphs of the disinfection phase were convex in type but approached linearity in the faster reactions. The logarithmic death-rate became maximal at about 90 % mortality and thereafter remained constant, though under the more acid conditions a somewhat lower rate was maintained. At pH 7·0 and 6·4 the curves were exceptionally straight.

6. Standardization of all the curves revealed a continuous change in shape with pH but, nevertheless, they could be placed in three closely knit overlapping groups which were best revealed by the variation in maximum death-rate.

7. The 50–99·99% mortality times were obtained either from the calculated regressions of log survivors on time over the linear portions of the curves or, outside that range, from the freehand curves. Maximum survival at all mortality levels occurred at about pH 6·5–6·6, i.e. close to the neutral point of pure water at 51° C. On both sides of this point sensitivity increased regularly but was abnormally high at pH 7·0 and 6·4.

8. Within these zones of abnormally high sensitivity the assessment of the effect of a given change in pH varied in amount and direction according to the mortality level chosen.

9. The enhanced resistance of a culture regenerated from the survivors of a disinfection at 51° C. and pH 7.0, as previously reported, could possibly have been largely due to a small increase in acidity but not to a slight shift towards alkalinity.

1. A food-borne outbreak of streptococcal infection in a cavalry regiment is described.

2. A controlled therapeutic experiment was carried out on the forty-nine patients admitted to hospital. Those given chemotherapy recovered more quickly than the controls, recovery being most rapid in the group given intramuscular penicillin.

3.Typical scarlatiniform eruptions were seen in ten cases. Streptococcal antitoxin appeared to prevent the occurrence of rashes, but had no significant effect on the duration of fever and toxaemia.

4. Upper respiratory complications supervened in ten cases. Evidence is presented which suggests that they were due to cross-infection.

1. An outbreak of Salmonella derby, involving sixty-eight patients, is described.

2. The organism was isolated from clinical cases, from carriers and also from dust in the wards, from a mouse and from a hand towel used by nurses.

3. The value of tetrathionate broth with subsequent cultivation on ‘SS’ agar as an aid to isolation of Salmonella bacilli was confirmed.

4. Cultural and biochemical characters of Salm. derby were recorded.

5. The antigenic structure of the isolated strains of Salm. derby was demonstrated, showing the presence of factor l and the absence of a minor flagellar antigen.

6. A serological response to Salm. derby infection was shown in patients, their sera containing H antibodies of a titre 1/20 to 1/320, whereas O agglutinins were absent at the time the tests were made.

7. Pathogenicity tests were performed on mice indicating the possibility of infection per os or by intraperitoneal injections. Mice were found to be potential faecal and urinary carriers.

1. An outbreak of gastro-enteritis in hospital due to Salmonella derby is described.

2. The probable pathways of infection are indicated diagrammatically (Text-fig. 2).

3. Attention is drawn to the importance of dust as an environmental source of infection in gastroenteritis in a closed community.

4. Methods of control including the detection of carriers, the avoidance of contact with anything that goes into an infant's mouth and the protection of exposed food from dust contamination are stressed.

1. An outbreak of typhoid fever in a Royal Air Force camp in the Middle East is discussed.

2. A total of 110 cases occurred of which 105 are analysed. The case-fatality rate was 10%.

3. Of the 105 cases 59% gave a positive blood culture. The percentages of diagnostic isolations from stools and urine were small.

4. Clearance tests of stools and urine showed that 8.4% of patients excreted Salm. typhi during convalescence.

5. Leucocyte counts during the first 2 weeks of the illness showed that only 30% of the patients had a count below 5000 per cu.mm.; 62% of these low figures were encountered in severe cases.

6. Autopsies on seven fatal cases showed considerable variability in the macroscopic appearance of the intestinal lesions.

7. Serological investigation confirmed that higher percentages of cases with low titres of O agglutinin were found in the severe and mild clinical groups, and that most O titres in the moderately severe cases exceeded 1:200.

8. Of the patients 52% showed Vi titres exceeding 1:20 during convalescence.

9. The significance of various findings is discussed.

1. The process of nuclear fusion and reorganization as it occurs in members of the Bacteriaceae is described.

2. The chromosomes behave as pairs at all times, the normal bacillus, of smooth morphology, contains two pairs.

3. The fusion nucleus contains three pairs and is preceded by a corresponding trinucleate bacillus.

4. One division of the chromosomes takes place in the fusion nucleus, and another during the process of redistribution of the chromosomes. The second division is followed by fragmentation, and return to the bacillary condition.

Recent research has even further emphasized the physiological dangers to which man is exposed when breathing gases at increased tensions. If he breathes air his activity under water is greatly limited by the problems of supply and compressed air illness. The latter is due to the formation of bubbles of nitrogen in the body on return to normal atmosphere. If he breathes oxygen, then he is in grave danger of oxygen poisoning, with convulsions, even at relatively shallow depths (Donald, 1947). During the recent war, mixtures of nitrogen and oxygen were employed for important work where the diver wished to go to considerable depths while carrying his own gases. These mixtures were varied in composition and rate of supply so that oxygen poisoning was avoided, and immediate rapid surfacing was possible, without compressed air illness occurring. However, this ingenious compromise is limited in its application, for as greater depths are reached, the oxygen has to be greatly reduced to avoid convulsions. The resultant rise in the proportion of nitrogen being breathed causes bubble formation in any but the shortest exposures. It is to be doubted whether the maintenance and meticulous supervision required, when using mixtures, will allow the use of these in the more normal conditions of peace-time. It has become increasingly apparent that the prolonged underwater survival of men requires pressure-withstanding devices in which he can exist at normal physiological tensions, i.e. atmospheric pressure. The rigid diving suit and submersible chambers, such as the bathysphere, are in their infancy; but the submarine, where the same conditions apply, is now a highly successful and developed method of underwater existence and locomotion. The further evolution of these devices, and of the submarine, depends mainly on engineering advances and not upon attempting to extend the comparatively rigid limits imposed by human physiology. The maintenance of a healthy atmosphere within a submarine is again a chemical and engineering problem which is capable of solution and constant improvement.

Certain sewage effluents have been found (Allen, Blezard, and Wheatland, 1946) to become highly toxic when treated with doses of chlorine much smaller than are required to give residual chlorine detectable by the ortho-tolidine test. Evidence from laboratory tests suggested that this toxicity was mainly due to a compound formed by interaction of the chlorine with small quantities of thiocyanate derived initially from gas liquor admitted to the sewage and surviving treatment at the sewage works. Key & Etheridge (1934) has shown that oxidation of the thiocyanate in a percolating filter or an activated-sludge plant, depends on the establishment of the necessary bacterial flora, and that a sudden increase in the concentration of thiocyanate in the sewage may result in a proportion of it being discharged in the effluent. Admission of gas liquor to sewage is common practice, and chlorination of such effluents would have serious effects on the living organisms, including fish, in surface waters to which they were discharged. Further work has revealed the nature of the compound responsible for toxicity, and has established the relation between toxicity and concentration of the substance in solution. An experimental study has been made of conditions affecting its formation during chlorination and of means of removing it from solution.

1. The fat metabolism of three healthy European adult males has been followed for periods lasting from 7 to 22 consecutive weeks; a fourth subject was observed for a much shorter period. During this time the subjects consumed: A, their usual diet; B, a diet including 1 lb. of standard bread, made from 95 to 100% extraction flour; C, a diet including 1 lb. white bread, made from 70% extraction flour; and D, their usual diet. During the usual diet periods A and D, standard bread was also eaten. While each subject consumed the type and amount of fat he was accustomed to, his variations in intake, especially during the experimental diet periods B and C, were small. The intakes of the four subjects ranged from 55 to 115 g. daily.

2. The average absorption of fat during the usual diet periods was 94·0%; during the standard bread diet, it also averaged 94·0%; during the white bread diet, it averaged 94·9%.

3. It is concluded that with daily fat intakes of the order used in this investigation, a diet rich in whole-grain bread when compared with one rich in white bread does not lead to any appreciable diminution in the amount of fat absorbed.

An individual dietary survey of 111 primiparae was carried out in Bristol during 1947. Compared with a group studied by McCance in 1938, these women were getting twice as much milk, more bread, potatoes, vegetables and fish; they were getting less meat, butter and margarine. 84 % were taking supplements of vitamins A and D.

Compared with the N.R.C. standard for pregnant women the diets were very poor, not one reaching the standard. It is felt that the N.R.C. standard for pregnant women is set too high. Compared with the standard for sedentary women there were deficiencies in vitamins B and C, the most marked being in nicotinic acid (74% of diets). As a group they appeared to be well nourished, only 8 % had a Hb below 80% and only one a plasma protein below 5·5 g./100 c.c.; there were no stigmata usually attributable to nutritional deficiencies. The only complication of note was toxaemia, which occurred in 15% of cases. The only deficiency in the diet common to all cases of toxaemia was in nicotinic acid. The mean intake of nicotinic acid was 2·0 mg. lower in the toxaemic group than the mean intake of nicotinic acid in the normal subjects. This difference was statistically significant. Evidence is presented which suggests that deficiency of nicotinic acid or vitamin B6 may be a predisposing factor in the production of toxaemia of pregnancy. The main cause of defective nutrition appears to be ignorance and not lack of money, this is an additional reason for the promotion of an intensive nutritional education programme.

The appointment of dietitians to ante-natal clinics is stressed as an important step in promoting education in nutritional matters during pregnancy.

The use and abuse of recommended allowances in pregnancy is discussed and the following diet is suggested as a reasonable practical allowance for pregnant women: calories, 2500; protein, 1·5 g. per kg. body weight; calcium, 1·5 g.; iron, 15 mg.; vitamin A, 3500 units (pre-formed); vitamin D, 800 units; vitamin B1; 1·5 mg.; riboflavin, 2·0 mg.; nicotinic acid, 14 mg.; vitamin C, 50 mg.

Gaseous insecticides, such as methyl bromide and methallyl chloride, are being used on an increasing scale against insects attacking stored products such as grain, tobacco, etc. Their use involves two possible dangers. In the first place, the worker may be poisoned either during the actual gassing operation or during the preparatory period. Secondly, there is the possible danger to consumers through the absorption of these furnigants into the stored product.

1. Of 1552 strains of Staph. pyogenes tested by the slide-agglutination technique, using the absorbed and unabsorbed sera suggested by Cowan, 74% of strains were identified while 26% remained untyped. Of untyped strains, half were inagglutinable while the remainder gave ‘indefinite’ results and remained unclassified. The introduction of two new sera, used diluted but unabsorbed, considerably reduced the number of untyped organisms but made little difference to the proportion of ‘indefinite’ strains. The method was simple and quick, but the variety of cross-reactions often prevented a clearcut differentiation of strains and the number of types identifiable was limited.

2. Of three methods of agglutination, titrations on glass slides were preferred because by this technique end-points were clearer than those obtained in a water-bath or by the method for determination of Vi antibody.

3. Agglutination of seventeen strains of Staph. pyogenes with homologous and heterologous sera showed that the use of unabsorbed sera was of limited value for typing because of the marked cross-reactions.

4. Christie & Keogh's division of Staph. pyogenes into nine types was promising but their absorbing methods allowed much antigenic overlap.

5. Experiments with absorbed sera showed that no single strain of Staph. pyogenes could be used successfully to absorb all sera. There appeared to be groups or pairs of types in which serologically the individual members resembled each other very closely and yet were not identical. In these instances the absorption of a serum by a heterologous strain nearly related to the homologous strain proved of most value in the preparation of specific sera.

6. A set of seventeen absorbed sera was prepared from Cowan's three types of Staph. pyogenes, from six of Christie & Keogh's type strains and from eight additional strains freshly isolated from staphylococcal lesions. With some absorbed sera there was specific agglutination with the homologous strain and no heterologous reactions, other sera reacted with several strains and could not be made specific.

7. Seven specific serological types were recognized while a further eight types showed less specific reactions and were identifiable by a pattern of reactions. A number of strains differed slightly one from another in their agglutination reactions, and it was not possible to decide whether these were additional types or variants within types.

8. In a small series of experiments the precipitin reaction, using unabsorbed sera, seemed of little value in the differentiation of strains of Staph. pyogenes.

9. Of 259 coagulase-positive strains examined during 1946 and 1947, all were identified by agglutination reactions, although they varied in their specificity; 67.5% of these strains were identified by staphylococcal bacteriophage reactions.

10. A preliminary comparison of serological and bacteriophage types showed a fairly regular but not complete correlation between the results obtained by the two methods. A number of serological types were regularly lysed by the same bacteriophage filtrates; a few were consistently untypable by phage indicating that filtrates had not as yet been found for them or that the strains were phage resistant.

Others which were not clear-cut in their reactions and which were recognized by patterns of reactions with both sera and phage filtrates did not always show a close correlation in the typing results.

11. The application of both serological and bacteriophage typing to the investigation of outbreaks of staphylococcal infection has proved to be of value in tracing sources and paths of spread of infection. In several instances the use of both methods of typing has led to conclusions which would not have been warranted if one method alone had been used.