1. The outbreak was one of bacterial food poisoning due to the consumption of infected milk.

2. The casual organism was B. enteritidis of Gaertner (Dublin).

3. A case of gastro-enteritis occured in an employee in the institution some days previously. This man's serum possessed agglutinins for for Gaertner'sbacillus, but the organism was not isolated from a specimen of his faeces taken 44 days after this attack.

4. This employee is supposed to have been the source of the organism which infected the milk. Two hypotheses are put forward to explain the mechanism of infection.

5. Servants who took the infected milk in their tea escaped infection. The milk was added to the tea in bulk and the experiments described satisfactoryily account for their escape.

(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.

Any description of the outbreaks of venereal disease is of necessity bound up with the migration of races, or parts of races, with wars and the consequent dislocation of the social system resulting from them. There are many inferences available from current writers showing how this contagious disease was spread and there is a good deal of reason to believe that some, at least, of the numerous cases of “leprosy” for which provision was made on frequent trade routes in past times were really cases of venereal disease.

For the past five or six years, epidemics of cholera have occurred every summer in Japan and the early cases in each outbreak are believed to have been imported from Manila or Shanghai.

Port quarantine in Japan has consequently been strict. Specimens of excreta from passengers and crew of vessels arriving from infected ports require to be examined bacteriologically and declared free before landing is permitted. The method is irksome and laborious though probably effective.

(1) Bacteriological examination of 1078 enterica-suspect cases showed that 112 (i.e. 10 per cent.) were due to Bacillus asiaticus Castellani. In the same series 12 per cent. were found to be due to B. typhosus or B. paratyphosus (A or B).

(2) The distribution of cases is widespread, both in time and space, and there is no special incidence on sex or age-group.

(3) The symptomatology of asiaticus parenteric fever is detailed and a description is given of the causal organism.

(4) There is some group-(agglutination) relation between B. asiaticus and the paratyphoid-Gaertner subgroup.

(5) Parenterica due to “intermediate organisms” other than B. asiaticus is believed to exist in Egypt. These will be dealt with in a later communication.

(6) Early haemo-culture in all enterica-suspect cases should be considered the diagnostic method par excellence. If the blood develops immune bodies as well, the diagnosis becomes definite.

The chemical changes which occur in the dissolved solids of sewage on discharge into sea-water have been investigated by several workers (see references 1–11). Some observation on the difference of these changes to those occurring in polluted fresh water have been made by Letts and Richards (6,11). In regard to waters whose saline composition is not such as to preclude their admissibility for potable purposes on this account, Liversidge(12) has made a brief communication on the variation in the free and albuminoid ammonia.

The method in which the mortality in childhood varies from age to age is a matter of very considerable interest. With each increase of unhygienic circumstances the death-rate among infants is well known to rise and it is commonly taken as a criterion of the measure of the unheathiness of the environment. In a rough way this is quite true but it is not the only criterion, any year of life might equally well be taken. The investigation in this note is based on a tabulation mande from the data published by the Registrar-General of England for the decade 1891–1900. In order tp make the statistics as homogeneous as possible the registration districts have been grouped accroding to the infantile mortalites, intervals of ten being taken in the unit. Thus those districts with death-rates between 80 and 90 have had their populations and deaths grouped togeather, those between 90 and 100 likewise and so on.

1. During the pre-epidemic stage of the spread of bacterial infection among mice, single deaths, or small groups of deaths, due to the specific infection being studied, are found to occur at considerable intervals before the rise of the main epidemic wave, and to afford a warning that such a wave is at hand.

2. In many cases there may be observed, during the same period, an increase in the daily mortality from all causes.

I should wish to express my thanks to Dr Major Greenwood for the interest he has shown in this investigation, and for much useful information with regard to epidemiological records. I am again greatly mdebted to my co-workers, Dr H. B. Weir and Dr G. S. Wilson, for their assistance in these experiments.

1. If a mouse-population, which has been exposed to the risk of infection, be dispersed into several small groups during the pre-epidemic stage, the total mortality will be far less than if the animals be retained as a single large group. The specific mortality will be reduced to a still greater extent.

2. During the period of dispersal, the mice forming the small groups will, in most cases, have passed through an extended pre-epidemic phase of the spread of infection. In so doing they will have acquired an appreciable degree of immunity.

3. If the small groups be later re-combined into a single aggregate, further deaths will occur; but the total mortality among a group of mice, which has been dispersed and then re-accumulated, will always be less than among a similar group, which has been retained from the commencement as a single unit of population. The specific mortality will generally show a still greater reduction.

It remains for me again to express my thanks to my colleagues, Dr H. B. Weir and Dr G. S. Wilson, for their assistance in this investigation.

In a recent series of papers, Flexner (1922), Lynch (1922), Amoss (1922a and b) and Webster (1922a and b) record the results obtained at the Rockefeller Institute in an experimental investigation of epidemics among laboratory animals. These experiments bear a close similarity to those which have been recorded in previous papers of the present series (Topley, 1919, 1921 a and b, 1922 a and b, and Topley, Weir and Wilson, 1921). Their publication affords an opportunity of comparing the results obtained in two independent enquiries, which have been carried out along slightly different lines, and of describing in more detail certain points in the general technique of our own experiments, which have an important bearing on the significance of the results obtained.

Contradictory opinions are at present held on the subject of bacterial standards of purity of water in India. My recent researches tend to throw some light on some of the causes of this divergence of opinion. The presence of frogs in water has been found to be responsible for an increase in faecal bacilli which, though negligible in the case of large bodies of water, is apt to be misleading in the case of waters of great purity. Stasis in reservoirs and passage through pipes may be responsible for a considerable increase in faecal bacilli in water, so that a mere increase in the number of faecal bacilli in a reservoir or pipe water does not necessarily indicate faecal contamination but may simply be due to stasis in reservoirs or flow through pipes. These findings lead to two conclusions of importance in regard to the bacteriological examination of water: (1) in testing for the bacterial efficiency of sand filters, samples should be collected from the filter well and not from the clear water reservoir where water is usually stagnant for some hours; (2) in interpreting the results of the examination of pipe waters the possibility of an increase of B. coli having occurred through multiplication in the pipes should always be borne in mind before inferring that such increase is indicative of faecal contamination or leakage in the mains.

While amino-acids in appropriate concentrations have long been known as valuable aids to bacterial growth, it does not appear to have been recognised that in relatively low concentrations they are often inhibitory.

Inhibition has been shown to occur with 10 out of 11 single amino-acids tested and with certain mixtures rich in amino-acids. The inhibitory concetration varies from 11 to 130 millimols per litre, or from 0·2 to 2%(wt./vol. ). It is of some intrest that the amino-acids inhibitory in the lowest concentration were the cyclic compounds—histidine, tyrosine, tryphane, phenylalamine. Of the chain compounds tested cystine was the most inhibitory.

Several organisus belonging to various groups of bacteria are susceptible of inhibition by amino-acids; certain intestinal organisms are not susceptible. The effect cannot be attributed to the physical effects of high concentration.

There is an apparent divergence between our results and those of workers who have recommended tryptic digests for stimulating the growth of some of the bacteria here shown to be readily inhibited by amino-acids. A suggested explanation of this divergence is that it is the products of partial protein digestion, the polypetides, which are mainly responsible for the effect of stimulating growth, not the amino-acids. A “polypeptide medium” might prove particularly valuable for bacterial growth.

A metabolism experiment with glycine in high but sub-inhibitory concentration showed that the amino-acid is broken down by Staphylococcus aureus, at this concentration.

The following paper contains a discussion of the results of the bacteriological examinations of samples of Grade “A” milk from two farms numbered 5 and 6.

The year 1921 was characterised by prolonged high temperatures and was one of great difficulty for the milk industry. It is, therefore, of interest to study the resultes of the bacteriological examination, and the keeping qualities of samples of Grade “A” (certified) milk which were examined during the period January 1st to December30th, 1921.

Since the Sachs-Georgi or flocculation reaction was first described as a paractical serum test for syphilis, the relationship of this reaction to the Wassermann or complements-deviation test has been a subject of some interest to serological workers.

Susceptible mice have been placed in contact with infective individuals of the same species, separated from them after a definite period, and placed in contact with a further group of normal mice. This process has then been repeated again and again, the number of groups exposed varying, in different experiments, from three to twelve. In this way the spread of infection has been limited to that occurring between any one group and the group immediately following it.

Under these circumstances infection has spread far less readily than was the cases in other experiments, in which the mice were retained as a single population, and in which infection could spread in any direction among all the individuals at risk.

In our previous studies on the spread of bacterial infection among mice, the resistance of the host has not been especially investigated; although the importance of this factor has been repeatedly referred to in discussing the experimental results obtained.

It has been found that the reductase test gives a considerably higher estimate of the number of organisms present in some milk samples than the plate method. This, however, is doubtless due to the fact that many colonies obtained by plating do not arise from a single cell but from chains of cocci and bacilli. Again the plate method takes no account of the anaerobic bacteria present in the milk.

When there are more than 100,000 organisms per cubic centimetre in the milk it would seem that the reductase test gives just as accurate an estimate as the plate method.

In its present form, however, the test would not be of service in grading of milk according to the bacterial standards now suggested.

(1) In media containing sodium sulphite, glucose, and iron salts, reduction of sulphite to sulphide is effected by B. typhosus, B. enteritidis (Gaertner), B. paratyphosus B, and various other members of the Salmonella group. No reduction was shown by B. paratyphosus A, and the various dysentery bacilli.

(2) The use of certain media containing sodium sulphite is recommended in attempting to’ isolate typhoid and paratyphoid B bacilli from excreta, water, milk, etc.

(3) It is suggested that the blackening which is brought about by certain members of the Typhoid-Paratyphoid-Enteritidis group in nutrient agar containing lead acetate is due, at least in part, to the reduction of sulphite im purities and that in order to get constant results with different brands of peptone an addition of sodium sulphite and a suitable fermentable carbo hydrate should be made to the medium.

1. No entamoebae, cysts, or other parasites were found.

2. Streptococci were present in the stools of all babies more than three weeks old, but only three haemolytic strains were isolated, which appears to be a lower proportion than occurs in adult stools.

3. Colon bacilli were present in the stools of all babies more than two weeks old, and haemolytic strains occurred in 12 per cent, of the specimens examined, that is in the same proportion as in adult stools.

4. Staphylococcus albus was much more commonly found than in adult stools and in greater abundance.

5. There was no bacteriological difference between the stools of the 78 breast-fed babies and those of the 13 artificially-fed infants, except that the haemolytic strains of B. coli occurred relatively more frequently in the case of the artificially-fed infants but owing to the small number of haemolytic strains isolated it would be unwise to lay too much stress on these figures.

In conclusion I wish to offer my sincere thanks to Dr Jewesbury, Physician to the Children's Department of St Thomas's Hospital, for supplying me with the necessary material and for information as to methods of feeding, and I am also greatly indebted to Professor Dudgeon and Dr Wordley for their constant help and advice.