The lecithinase and haemolytic activity of thirty strains of Cl. welchii isolated from food, faeces, and soil, was studied. The strains from foods produced smaller amounts of lecithinase and were, in general, less haemolytic than the strains isolated from soil and faeces.

The haemolytic activity of Cl. welchii on erythrocytes from different animal species displayed considerable variation. Sheep erythrocytes were the most sensitive to the action of alpha toxin, whereas rabbit blood was most sensitive to haemolysis by theta toxin. The degree of haemolysis was also dependent upon the concentration of the enzyme, and temperature and length of incubation.

The haemolytic activity of commercial lecithinase was observed to be similar to the haemolytic activity of the alpha toxin of Cl. welchii. This finding provides further evidence that the haemolytic and lecithinase activities of Cl. welchii are due to one substance, the alpha toxin. Exposure of commercial lecithinase to heat resulted in the destruction of its haemolytic properties.

Varicella is a vaccine-preventable infectious disease. Since 1 December 2018, the varicella vaccine has been included in the local Expanded Programme on Immunization (EPI) in Wuxi, China, and children born after 1 December 2014 are eligible for free vaccination. To evaluate the effect of varicella vaccination in Wuxi city, we selected 382 397 children born from 2012 to 2016 as subjects. Their disease data were obtained from the Chinese Disease Prevention and Control Information System, and their vaccination data were obtained from the Jiangsu Province Vaccination Integrated Service Management Information System. The incidence of breakthrough varicella cases increased in the first 4 years and reached the peak in the fifth year. With the increase of vaccination rate, the incidence of varicella decreased significantly. The vaccine effectiveness (VE) was found to be 88.17%–95.78% for one dose and 98.65%–99.93% for two doses. Although the VE per dose decreased from 99.57% in the first year to 93.04% in the eighth year, it remained high. These findings confirmed the effectiveness of varicella vaccination in children, supported the use of a two-dose varicella vaccination strategy to achieve better protection, and provided important insights into the optimal vaccination strategy for varicella prevention in children.

(1) These experiments prove that the fumigator is safer to use than the dumping fixture, because high concentrations of the poison gas are avoided, so that dangerous pockets are not developed.

(2) The poison gas is more evenly distributed over the different parts of the section of the ship under treatment.

(3) High concentrations, however, can be developed^ at will in any part which requires special attention.

(4) The maximum concentrations of the poison gas were obtained in every part of the section in a shorter time, when the fumigator was used, than when the dumping fixture was employed.

(5) The artificial ventilation caused by the fan, which is capable of blowing into the section 500 to 1000 cubic feet of fresh air per minute, according to the speed of the motor, materially assists the rapid clearing of the poison gas from the ship, after it has accomplished its work. It is thus possible to complete the fumigation and ventilation of a ship in 3 hours using the cyanide fumigator, while more than 4 hours are required for the dumping fixture.

(6) Even more important is the fact that smaller quantities of cyanide can be used with greater efficiency in the fumigator, than larger quantities, with less efficiency in the dumping fixture.

(7) The general conclusion is arrived at, that, from the point of view of efficiency, safety and economy, the fumigator is superior to the dumping fixture. Creel has shown that, in respect to the time required for completing the fumigation, and in respect to the thoroughness of the process, both in killing rats and insects, the dumping fixture is superior to the Clayton gas machine. It follows, therefore, that the cyanide fumigator is very much superior in these respects to the Clayton gas machine.

A new form of photo-electric photometer or colorimeter is described which permits of accurate and objective readings in a wide range of colorimetric work with small quantities of solutions. The instrument is of the null-point type and hence requires calibration to suit the particular estimation.

The writer is indebted to the Earl of Moray Fund of the University of Edinburgh for financial assistance towards the expenses of the earlier part of the work.

The original model was made by A. H. Baird of Edinburgh, the model described above by Wm. Watson and Sons, London, to whom, and to Mr W. E. Watson-Baker, I am indebted for suggestions on a number of points.

The aim of this study was to determine the extent to which selective under-coverage of births to mothers more likely to be at risk of HIV-1 infection will result in a significant underestimation of the true neonatal seroprevalence. Census data, local birth statisties, maternity data and data from the prevalence monitoring programme were used to produce a model to predict the effects of under-coverage in the uptake of neonatal metabolic screening which has been observed in babies with a mother of ethnic group black African. The adjustment factor which allows for under-coverage is the relative inclusion ratio (RIR); the probability that samples from a group at different risk of HIV infection were included in the survey divided by the probability of inclusion for samples from all other babies. The RIR was found to be close to unity (0·97), indicating a minimal bias. Under usual conditions only if the relative inclusion ratio (RIR) declined to values of 0·87 or below would there be a substantial bias. Despite some selective under representation, the results obtained from the Unlinked Anonymous HIV Monitoring Programme Dried Blood Spot Survey would seem to identity levels of prevalence in the population of child-bearing women with a good degree of accuracy and remains a useful tool for resource allocation, planning of services, provision of care and counselling.

1. A clinical and biochemical study of a group of thirty patients from northern Portugal shows that they were suffering from a mild form of pellagra with no signs of severe malnutrition or of associated deficiencies except dental abrasion caries and pyorrhoea.

2. The diet of these patients in most respects was chemically satisfactory. Apart from a very low consumption of animal protein the gross intake of calories, total protein minerals and vitamins, including nicotinic acid, was satisfactory.

3. Since the syndrome was completely cured by nicotinic acid, it is suggested that the main characteristic of a diet on which pellagra is likely to develop is not a shortage of nicotinic acid, but a lack of high-grade protein.

4. A maize diet, satisfactory so far as calories and total protein are concerned, may produce pellagra because maize proteins are short of certain essential amino-acids. Other cereal diets may also produce pellagra if the general level of nutrition is very low.

5. The syndrome may be cured either by very large doses of nicotinic acid without change of diet or by moderate doses accompanied by abundant animal protein.

The practice of using preservatives in the process of making cider is very widely spread, and moreover is much encouraged by the makers of the preservatives.

Resistance of faecal Escherichia coli to ampicillin, tetracycline, sulphamethoxazole and gentamicin was studied in patients admitted to seven different departments in two hospitals. The resistance to ampicillin, tetracycline and sulphamethoxazole in the seven patient groups was 27–57%, 26–56% and 35–63%, respectively. Resistance to gentamicin was found in only one department. An E. coli flora predominantly resistant to ampicillin, tetracycline or sulphamethoxazole (> 50% of the E. coli strains in a faecal sample resistant) was found in 10–38%, 4–30% and 21–35% of the samples. A cross-sectional study focusing on the influence of the use of antimicrobial agents on the occurrence of resistant strains revealed a positive correlation between the annual turnover of broad-spectrum penicillins in various departments and the occurrence of predominantly ampicillin-resistant E. coli strains in these departments.

The following paper gives some results of a series of experiments on the bactericidal power of various sources of ultra-violet radiation. The “power” of the source was in each case measured by the quartz-cadmium photo-electric cell described by the authors (1925), and it is shown that very definite and practically useful correlations exist between the cell reading and this typical abiotic action.

In general, it may be said that bacteria once introduced into a culture of trypanosomes tend to outgrow and check the development of the flagellates. In exceptional instances, however, the bacteria thus introduced exert little of no interference and may be even apparently beneficial. While in the former case the trypanosomes soon die out, in the latter instance the mixed cultures may be kept for six months or longer.

In the first report (vol. vi. p. 450) we described several series of experiments which had as their object the determination of the relative importance of the Indian rat flea, Palex cheopis, and of actual close contact in the absence of fleas in the dissemination of plague from animal to animal. These observations were carried out in a series of small godowns or cabins, which were built especially for the purpose. The experiments which we have now to put on record are a continuation of those already published. They were carried out during the non-plague season of 1906 and the plague season of 1907.

Although multiple cases of acute rheumatism have been observed to follow waves of streptococcal infection in institutions (see Green, p. 369) there is doubt as to whether acuter heumatism itself becomes epidemic under such circumstances or whether the element of infectivity lies in the preliminary throat infection as concluded by Sheldon (1931).

A study was made of factors leading to loss of working time in a local group of 144 women voluntary factory workers. The majority were single women whose interests centred in their families. One-third of these 144 women, owing to disability of some near relative, had home duties which they realized were sufficiently heavy to interfere at times with their factory work; a contributory cause of absenteeism was ill-health, ascribed by many workers to cold and draughty working environment. Examination of the factory records showed more than twice the rate of absenteeism due to certified sickness among women with home ties and responsibilities.

This study was made possible by the willing cooperation of the Factory Management and their Welfare Department and of the women workers concerned.

H. Smidt in a recent note on the reduction of methylene blue by means of milk confirmed the results of Schardinger that a mixture of formaldehyde and methylene blue is decolorised by the action of milk. This reaction depends on the presence of a ferment—a catalase—in the milk, and, as this ferment is readily destroyed by heat, serves as a very simple method of determining whether a given sample of milk is “raw” or not. By way of conclusion Smidt stated that he thought this test might be of still further utility in that it might be possible to estimate the degree of bacterial contamination of the milk by its means. If such a comparatively simple test could be employed, in an easy and effective fashion, it would be of immense service, as, owing to the rapidity with which it can be carried out, the milk could be examined before distribution.