An outbreak of food-poisoning is described in which the B. morbificans bovis (Basenau) was the causal agent. The position of this type in the Salmonella group as classified by Bruce White has been confirmed by analysis of the antigenic properties and agglutination reactions (including absorption of agglutinin) of the strains isolated in the outbreak.

1. The three organisms B. pyocyaneus, B. fluorescens-liquefaciens and non-liquefaciens form a closely related group of organisms both biologically and also by reason of their behaviour towards disinfectants.

2. Bacteriological observations support the view that germicides can naturally be divided into two classes, viz. “chemical” and “physico-chemical,” their actions on micro-organisms depending respectively on

(1) Chemical reactivity with protoplasmic constituents.

(2) Denaturation or precipitation of the cell proteins.

3. B. fluorescens non-liquefaciens and related organisms are selectively attacked by “physico-chemical” germicides, e.g. phenol, whilst B. coli is less sensitive to their action, but is particularly susceptible to the “chemical” disinfectants, e.g. quinones.

The B. fluor. non-liq. group is also more readily affected by hot water than B. coli.

4. Substitution of various groups into the benzene nucleus in the case of aromatic disinfectants affects the germicidal power on B. coli and B. fluor. non-liq. unequally, with the result that the selective action and differentiation may be obscured or even reversed in the case of the substituted derivatives.

5. B. fluor. non-liq. is more sensitive than B. coli to the action of reducing agents, and this factor also affects the degree and nature of selective action, sometimes resulting in the classification of “chemical” germicides in the “physico-chemical” group.

6. Selective action is not affected by changes in experimental conditions, such as temperature and period of disinfection, nature of culture medium, number of bacteria present, or physical state of the disinfectant. The susceptibility of B. fluor. non-liq. to the action of hot water, and such germicides as phenol and alcohol, is thus probably associated in some way with its internal colloid state.

7. The analogy between the action of hot water and that of the alcohols and phenols is borne out by preliminary experiments with the thermophile bacteria (heat resistant). These organisms are somewhat less sensitive to phenol that B. coli, and more susceptible to p-nitrosodimethylaniline.

Since disinfectants containing hypochlorites have been used for the sterilisation of dairy utensils, and it has been claimed that such disinfectants are more efficient than steam sterilisation, it seemed advisable to study the question in the interests of the Milk Industry. The efficiency of three proprietary disinfectants (A, B and C) has, therefore, been investigated.

The analysis of an epidemic of influenza in the New Zealand division of the Royal Navy confirms the following hypotheses which were suggested by previous studies of the same and other diseases.

(1) The type of influenza in different places, especially if they are more or less isolated areas, such as islands or ships, tends to assume special characters as regards infectivity, virulence, and clinical type1. In this respect the influenza virus, or viruses, are only following a well-known biological “law,” namely, that isolation tends to encourage the evolution of new varieties and species. A classical example of this “law” is found in Darwin's reference to the fact that each island of the Galapagos Archipelago has its own special flora and fauna—similar to but yet different from that of the other islands.

(2) One wave of influenza, even if of a different type, will confer considerable immunity to a subsequent wave not only on the victims attacked, but also on those who apparently escaped infection during the first wave.

(3) The brunt of the morbidity of influenza (and other infections) is borne by recruits and junior ratings, not because they are, on the whole, younger, but because they have had less time than the senior men to adapt themselves, by means of auto-vaccination, to the bacterial environment of crowded ships or barracks.

The effect of bacterial adaptation to environment is often overlooked. Hence other factors, such as physical fitness, are often given more credit than they deserve as preservers of the public health.

(4) Senior ratings mixed with recruits suffer a higher morbidity from infectious disease than they do under similar circumstances in the absence of recruits. This statement, if true, should have a most important practical bearing on military medical administration. The phenomenon is probably due to increased velocities of infection (due to the higher infectibility of the recruits) breaking down the herd immunity of the senior men.

(5) In this epidemic New Zealanders suffered more from influenza than the British sailors not, as usually supposed, because of the mere fact of being born in New Zealand, but because all the recruits and the bulk of the junior ratings were New Zealanders.

(1) Strains of B. pestis, kept in culture for 7 and 9 months, showed no loss of virulence.

(2) Virulent strains, when subjected to passage through an immunised Cricetomys gambianus (African pouched rat), suffer distinct loss of virulence for this species, and virulence is not regained in culture or on repeated passage through susceptible C. gambianus. The so-called avirulent plague bacillus, obtained in this way, appears to be a rough variant. It differs in micro-scopical appearance from the ordinary virulent forms, tending to the appearance from the ordinary virulent forms, tending to the appearance of involution forms, which develop in salt media.

(3) As regards immunising properties:

(a) Vaccine prepared from virulent strain gives considerable protection against infection with virulent strain.

(b) Vaccine prepared from virulent strain gives no protection against infection with avirulent strain.

(c) Vaccine prepared from avirulent strain gives little or no protection against infection with virulent strain.

(4) Animals, which recover from infection with an avirulent strain, are immune to subsequent infection with virulent strain.

1. Though Shanghai is in close communication with ports in which plague is endemic, it has not suffered severely.

2. The number of human cases is small compared with the number of plague-infected rats found.

3. Both X. cheopis and C. fasciatus are found. Reasons are given for considering that X. cheopis is the chief agent in spreading plague, and that infection, being unlikely to reach Shanghai during the season when this flea flourishes, has difficulty in gaining a foothold.

4. The discrepancy between the number of cases of human and rat plague may possibly be explained by the habits of C. fasciatus.

Two epidemics among mice are described that were closely associated with Morgan's No. 1 bacillus. In both of these epidemics the mice, which were fed on oats and raw beef, were found at autopsy to be suffering from peculiar lesions—an advanced degree of anaemia, pale and swollen kidneys, and general pallor and dryness of the tissues—not hitherto encountered in any other epidemic. Evidence is advanced to show that Bact. morgani was the specific cause of these epidemics; and it is suggested that the peculiar lesions described were the result of a chronic intestinal infection with this organism.

The close analogy existing between the bacteriological findings in summer diarrhoea and in our experiments is discussed. The tentative conclusion is advanced that summer diarrhoea is not a bacteriological entity, but is a disease that can be caused by a number of different members of the non-lactose-fermenting group.

FROM time to time certain organisms, all closely similar, have been encountered in this laboratory which from their unusual occurrence and unfamiliar behaviour presented some difficulty in their identification. An account of some of them and of the cases from which they were derived is here given, and an attempt is made to correlate the organisms. If the result of the investigation shows that they belong to a single group of pathogenic bacilli, the important fact will be illustrated from the short accounts of the cases that a wide range of clinical manifestations may be met with in association with this group of bacteria.

A Report of the Medical Research Council (1926) was published last year on the results of extensive investigations, carried out under the auspices of the Scottish Child Life Committee of the Medical Research Council, on the environmental and parental conditions affecting the growth and nutrition of the slum child. This showed that while there were great differences in the growth and nutrition of these children as indicated by weight and height, these differences could not be correlated with such environmental factors as income and air space (degree of crowding), nor with the parental factor maternal health, while the evidence adduced did not indicate that diet was a determining factor. In fact the only significant correlation discovered was with the efficiency of the mother.

Guinea-pigs living on a diet restricted in quantity but not deficient in vitamin C survived inoculation with T.B. but half as long as others which had received a similar diet in abundance.

Sodium chaulmoograte did not inhibit the development of the omental tumour that appears in rats after intraperitoneal inoculation with tubercle bacilli.

On the other hand, there was some evidence for assuming that a large excess of fat-soluble vitamins in the diet, as supplied by cod-liver oil, inhibits the formation in rats of these tuberculous tumours, but such evidence was by no means conclusive.

Similar inhibition of omental infection was obtained on exposing rats to ultra-violet light.

Ultra-violet irradiation or the inclusion of large amounts of cod-liver oil in the diet of the rats produced a slight but constant leucocytosis.

No evidence was obtained that lack of fat soluble vitamins in their diet renders tubercle infected rats susceptible to tuberculin shock.

1. The development in typhus fever blood of agglutinins for a bacillus of the colon-paratyphoid group, which was isolated in 1921 from the faeces of a typhus case is shown to be a frequent occurrence in the disease as met with in Ireland, Poland and Syria. The bacillus has preserved its agglutina-bility up to the time of writing—a period of five years. Owing to its similarity to a bacillus previously isolated by the writer and which was designated bacillus “U,” this bacillus has been named B. agglutinabilis “U2.”

2. It has been shown that bacteria preserved in alcohol even for 3 years are sensitive for use in the serological test, and that sera to which equal volumes of pure glycerine have been added retain their agglutinins for atleast 5 years.

3. Five strains of B. proteus “X 19” fermented salicin with the production of acid and gas. Ordinary Proteus strains had no action on this glucoside and neither had the anindologenes strain “Kingsbury” although belonging to the “X 19” group.

4. Strains of B. proteus “X 19” show great differences in their sensitiveness to typhus fever agglutinins.

5. Views which have been advanced to explain the Weil-Felix reaction are discussed and the conclusion is reached that to label it as an instance of paragglutination does not account for the rise and fall of the agglutinins—agglutinins which are formed not only for B. proteus “X2” and “X 19” but for certain strains of the B. pyocyaneus and colon-paratyphoid-typhoid groups.

The standing difficulty with the normal bulbed pipette is to clean the inside surfaces of the bulb. With a new pattern introduced by the writer the whole of the inside surface can be reached for cleaning. Pipettes have been made to this design by Messrs Baird and Tatlock, Ltd. (London).

THE production of a fibrosis due to inhalation of haematite in man has already been disucssed by Goadby (1925). The following experiments were made to see what effects were produced by exposing guinea-pigs to the dusts of (a) haematite (Fe2O3) and (b) levigated iron.

Finacial assistance towards these experiments was very kindly rendered by the Mines Department, to the Inspectors of which I am also indebted for the haematite powder from Cumberland.