Workers in factories and a postal sorting office were questioned concerning their subjective thermal sensations, and the replies assessed according to a scale of standard sensations. Measurements of the thermal environment were made concurrently. The investigation was confined to workers engaged in light or sedentary activity during summer months in southern England.

The upper limit of the comfort zone is determined in terms of the temperatures at which more than 20% of people questioned experienced thermal discomfort.

Discontinuities in the linear relationships between thermal sensation, described on a numerical scale, and the thermal indices of the environment are shown to occur under conditions which suggest the onset of sweating beneath the clothing. The comfort zone is also determined in terms of these critical temperatures.

The regression constants relating thermal sensation to thermal conditions are determined, and the optimum conditions for comfort are deduced. The accuracy of prediction of thermal sensation from thermal measurements is examined.

The importance of clothing in requirements for thermal comfort is illustrated in two ways. Postal workers wearing regulation uniform were found to require conditions cooler than those required by factory workers wearing clothing of their own choosing. Male and female factory workers were found to require thermal conditions not significantly different, this being attributed to their selection of clothing appropriate to their personal thermal requirements.

I am indebted to Prof. G. P. Crowden for granting facilities for this research and for encouragement throughout. Dr T. C. Angus and Dr T. Bedford gave valuable advice, and Mr P. J. Williams rendered technical assistance. The co-operation of the managements and workers at the factories was greatly appreciated.

1. In gastro-enteritis of babies caused by pathogenic varieties of Bact. coli the infection extends up the whole length of the small gut. Quantitative bacteriological examinations showed the contents of the upper intestine to harbour Bact. coli in numbers usually found only in faeces.

2. Bact. coli O 111, O 55, O 26, etc. are pathogens.

3. The syndrome of gastro-enteritis of babies associated with Bact. coli resembles cholera clinically, pathologically and bacteriologically.

4. There is a place in bacteriology for quantitative tests as distinct from qualitative tests.

I owe my thanks to many people: to Dr A. H. James for teaching me his methods of getting samples of duodenal juice; to Prof. A. G. Watkins, Dr P. T. Bray, Dr Emrys Harries, Dr S. Rosehill, Dr Bowen Owen and Dr W. R. Nash for allowing me access to their patients; to Dr T. E. Parry, Dr W. Mackay and Dr R. D. Gray for allowing me to attend and collect specimens from autopsies; it would be ungracious not to thank several ward sisters to whom I must have been a great nuisance. To my technician John Smith I am exceedingly indebted.

1. Production figures are given for a small mouse colony.

2. High productivity depends upon careful selection of breeding stock.

3. This selection has been based on an analysis of individual records. Both the keeping and the analysis of records are easy and simple.

4. In addition to providing a basis for selection, these records make possible a forecast of future production.

I particularly wish to thank Miss D. Lawrence, the animal technician whose skill in looking after this colony has contributed so much to its successful performance.

1. The results of an investigation into the clinical, epidemiological and bacteriological features of impetigo contagiosa, with special reference to the type identification of staphylococci and streptococci, are reported and discussed.

2. Of 106 impetigo cases studied, Staphylococcus aureus was isolated alone from 86 lesions (81 %), Streptococcus pyogenes alone from 6 (5·6 %), and a mixed growth of Staph. aureus and haemolytic streptococci in 14 instances (13·2 %).

3. Of the 100 strains of Staph. aureus isolated from impetigo lesions, 63 were identical in phage type (‘type 71’), and a further 17 were closely related (‘weak 71’).

4. Only one representative of ‘type 71’, and 9 of ‘weak 71’, were obtained from 164 strains of Staph. aureus from 200 persons in three control groups.

5. Of 90 strains of Staph. aureus from impetigo lesions, 64 (71 %) were resistant to penicillin. Of these penicillin-resistant strains, 54 (84 %) were of ‘type 71’, or close variants.

6. Strep, pyogenes was probably causative in at least 6 of the 18 patients yielding this organism from lesions; it was presumed to be a secondary invader in the remainder.

7. It is doubtful if nasal carriage is of importance in the epidemiology of impetigo.

8. It is concluded that there is a specific ‘type’ of staphylococcus associated with this form of impetigo.

The returns relating to naval personnel who were reported to the Admiralty to have acquired non-surgical jaundice between 1944 and 1947 were examined.

Where the dates of onset of illness and of inoculation were available, the numbers who developed the illness within 11–40 days of inoculation were greater than the numbers to be expected if there was no association between the dates of onset of illness and the dates of inoculation. During 1945 the observed numbers were also greater than the expected numbers when 41–70 days intervened between inoculation and the illness.

The interpretation and practical implications of the findings are discussed.

This paper is published by kind permission of the Medical Director General of the Navy, Surgeon Vice-Admiral Sir Alexander Ingleby-Mackenzie.

I am indebted to Dr F. O. MacCallum for his continued interest and for invaluable suggestions; to Dr J. O. Irwin for scrutinizing the script; to Miss H. M. Ferres who applied the statistical tests to the figures in Table 1; to Surgeon Commander M. A. Rugg-Gunn, Royal Navy, for the information about the ratings' pay books, and to Senior Commissioned Wardmaster J. L. T. Burns, Royal Navy, and Sick Berth Petty Officer (L) D. E. Lee, Royal Navy, who tabulated the numerical data.

1. In bacteriological investigations of stretches of water an estimate of the number of a certain type of bacterium in a unit of volume of the water is required so that the pattern of the pollution of the area can be discerned. Usually it is known or guessed that the density of bacteria,δ say, lies in a range δL up to δH. Several samples of water are taken and each is tested for a positive reaction which would indicate the presence of at least one bacterium of the type being searched for. When it is assumed that bacteria are spread in a Poisson manner through the water in each sample an estimate of their density can be made from the number of positively reacting samples.If the range δL to δH is large it is unlikely that one volume of water for each sample will give a very efficient estimate of the density;e.g. if this volume is in an average position with respect to (δL to δH), say, 2/(δL +δH), and the true density is near an end of the range, all the reactions are likely to have the same sign and the sample gives no discrimination. Even worse estimation for some densities will occur if a very small or very large volume is used. The setting of reasonably sized confidence intervals for the density requires a series of volumes designed to locate the density with about equal accuracy no matter where it is in (δL to δH). Hence the usual set of volumes is the dilution series discussed by several writers, for example recently by Cochran (1950).

Sera of 2017 subjects were tested by the slide-agglutination method for the presence of agglutinins to Candida albicans. 638 (31·6%) were positive, and more females than males had positive sera.

The results are reported of quantitative agglutinin estimations in 501 subjects, 121 of whom were known to be infected with C. albicans.

The significance of C. albicans agglutinins is discussed.

Enteric fevers are common in the Gold Coast, where their incidence is increasing owing to insanitary urbanization. Children and migrant labourers form the bulk of the patients. Typhoid fever accounts for three-quarters of the cases, but paratyphoid A and paratyphoid C also occur. The Widal test has attained renewed importance in early diagnosis since the introduction of chloramphenicol, and gave a presumptive diagnosis within 24 hr. in two-thirds of the cases. ‘Normal’ agglutinin levels were determined in 200 sera sent for the Kahn test, and provide data for interpreting the Widal test in the Gold Coast. Low titre H agglutinins in the sera of normal people are thought to indicate past vaccination or infection, but low titre O agglutinins are probably unrelated to either. Agglutination of a Salm. typhi H suspension by normal sera suggests that one adult African in eight in the Gold Coast has suffered from typhoid fever.

I have to thank Lt. Col. H. J. Bensted, O.B.E., M.C., for kindly providing Standard agglutinating sera.

My thanks are also due to Messrs D. Gellatly, A.I.M.L.T., K. C. Lisle, E. S. Martinson and A. T. Nartey for their technical assistance at various times during the past 2½ years.

I am indebted to Dr George Watt, M.B.E., acting Chief Medical Officer, Gold Coast, for permission to publish this paper.

Lanoline-water cream containing 1% of antibiotic was applied for 7–14 days to the anterior nares of 124 carriers of antibiotic sensitive staphylococci. Nose swab cultures, examined during the administration of the cream, were negative for Staph. pyogenes in all carriers who received oxytetracycline, and in 80, 75, 70 and 67% of those who received penicillin, chlortetracycline, streptomycin and chloramphenicol respectively.

Seventy per cent of carriers gave nose-swab cultures negative for at least 2 weeks, 50% for at least 4 weeks and 25% for at least 20 weeks after the cessation of treatment. Over the same period only 1% of a control group ceased to be carriers.

The nares of 20% of carriers receiving antibiotic were temporarily colonized with antibiotic-resistant strains, but in only one case (0·8%) did the resistant organism persist throughout the period of examination.

The use of this method of controlling staphylococcal carriage in preventing staphylococcal infection is discussed.

I wish to thank Prof. T. J. Mackie for his advice.

Vaccinia virus which has been inactivated by exposure to ultra-violet irradiation under strictly controlled conditions produces an immunity response in rabbits and monkeys. This can be measured by relative insusceptibility to challenge with living virus and by the titration of circulating antibody.

Experiments with small doses of living virus in excess of those that might have been given accidentally indicate that the immune response to the irradiated material was not due to traces of living virus that had escaped detection.

There is a logarithmic relationship between exposure to irradiation and destruction of virus. The exposure necessary to produce complete inactivation can be deduced from a knowledge of this relationship. Excessive exposure destroys the antigenicity of the preparations.

The antigenicity of irradiated virus can be preserved for at least 6 months at 4°C. and at least 2 months at 37°C. by drying from the frozen state.

Circulating antibody is detectable in rabbits for at least 22 weeks following immunization, and a single subsequent reinforcing dose is followed by a secondary immune response.

The possibility that preliminary immunization with irradiated virus may diminish the risk of complications and reduce the severity of the reaction to subsequent Jennerian vaccination with living virus is discussed. This material may provide a basal immunity in those individuals in which vaccination is contraindicated.