1. In the intradermic test virulence of “morphological diphtheria bacilli,” 0·2 c.c. containing 100 million organisms is injected. The control guinea-pig receives 500 units of antitoxin the night prior to the test. The test animal receives 125 units six hours after the injection of the cultures. A known virulent organism is always injected as a control; 12 to 20 cultures can be tested on one guinea-pig.

Of 2368 swabs received, 1388 (59 per cent.) showed morphological C. diphtheriae. Fromthese 1286 pure cultures were isolated (92·7 per cent.). In 234 positive swabs from cases of clinical diphtheria, in a series examined under very favourable conditions, morphological C. diphtheriae were obtained in 231 (98·7 per cent.) and of these 229 (99·1 per cent.) were virulent. In 758 positive cultures from carriers morphological C. diphtheriae were isolated in 715 (94 per cent.); 50 per cent. were virulent C. diphtheriae, 39 per cent. avirulent, 3·6 per cent. of Hofmann group, 0·3 per cent. Xerosis and 6.4 per cent. unclassified diphtheroids.

3. Only one culture of intermediate virulence was found, i.e. uncertain reactions occurred with a dose of 100 million organisms while clear reactions occurred with 1000 million.

4. Out of 626 positive cultures from cases of diphtheria, both virulent and avirulent bacilli were isolated in two instances, once from the throat and once from the nose.

5. A monovalent antitoxin (Park Williams 8) nenutralised all of 819 virulent strains.

6. Amongst 39 cultures obtained from the ear in post-diphtherial conditions, virulent C. diphtheriae were isolated fourteen times.

7. Impure primary (“field”) cultures gave reliable results (94 per cent.) when more than one-third of the organisms seen in the smear made from the overnight culture were morphologically C. diphtheriae. If fewer C. diphtheriae were present in the smear th e primary culture gave uncertain results.

1. “Antigens” of varying sensitivity may be prepared by coating a dispersion of gum benzoin with saponin.

2. Using suitable dispersions so prepared a zone of precipitation is observed which is more extended for specific than for normal sera. Differentiation is more pronounced as the region of the isoelectric point of the globulin is approached.

3. Precipitation is effected by the ions of salts present in the solution discharging the negative antigen suspension which has been sensitised by the protein of the serum.

4. The mechanism of sensitisation is described.

5. Both albumins and globulins can protect or sensitise gum benzoin suspensions, the effect depending on an appropriate dilution. This effect occurs qualitatively irrespective of the hydrogen ion concentration of the medium. Quantitatively the position of the zone of precipitation and its extent is contingent on the reaction of the medium.

6. The euglobulin fractions of normal and of luetie sera deprived as far as possible of their lipoids can be differentiated both by the Wassermann test, and by precipitation tests.

7. Delipoided euglobulins from horse serum will yield a Wassermann positive reaction when used in certain concentrations. In more concentrated solutions an anticomplementary effect is exhibited.

8. Evidence is presented for the view that the euglobulins of specific sera differ rather in their composition or state of aggregation than in quantity from the euglobulin of non-specific sera.

9. The changes in sensitising power and in the Wassermann reactivity of euglobulin caused by repeated freezing or exposure to ultra-violet light run a parallel course.

10. Attempts to change the Wassermann properties of normal sera are briefly described.

The analysis of a series of haemolytic streptococci of scarlatinal origin by agglutinin absorption experiments has revealed the existence of three chief types. Among 81 strains from scarlatinal throats 37 have been shown to belong to one or other of the three types; 12 have been classified as Type 1, 14 as Type 2 and 11 as Type 3. In addition, two strains have been found which absorbed the agglutinin from both Types 1 and 3 sera.

(1) The source, cultural characters and serological properties of a new food-poisoning type of Salmonella are described.

(2) The value is emphasised of Andrewes' discovery of the group and specific phases in Salmonellas.

(3) Alteration of phase from group to specific can be produced by growth in group serum and vice versa. This device is useful in determining the sero logical type of strains which persistently appear in the group phase only.

Four outbreaks of food-poisoning are described in which over 100 cases in all of gastro-enteritis occurred, one being fatal. In each outbreak the infecting bacteria were indistinguishable culturally and in serological behaviour from the “G” strain of B. suipestifer.

The reasons are given for following Andrewes and Neave and classifying these as B. suipestifer. (sub-group II).

This report is a contribution to the joint investigation, organised by the Ministry of Health, into the bacteriology of Scarlet Fever. It has been carried out with the aid of a grant from the Ministry to whom I am indebted for permission to publish these results.

An epidemic of enteritis due to infection of milk with a Flexner type dysentery bacillus, causing over 1000 cases and 72 deaths, occurred in Aberdeen in 1919, and has previously been recorded in the Journal of Hygiene(1). Another mild-borne outbreak of enteritis, causing 110 cases and no deaths, occurred in 1923, and has similarly been recorded(2). The cause of this outbreak was not determined, but was assumed to be due to a living bacillus of unrecognised type. In July, 1925, there occurred a further extensive outbreak of enteritis, which has been proved to be due to infection of milk with Bacillus enteritidis Gaertner, and as the infection has been proved to be of bovine origin, the Gaertner bacillus having been isolated from the udder and flesh of the diseased cow, as well as from the infective milk, it appears advisable to record the out-break in considerable detail.

In the Medical Research Council's Special Reports, Nos. 91 and 92, and in the Journal of Hygiene, vol. XIV. No. 1, July, 1925, W. G. Savage and P. Bruce White stress the desirability of restricting the term “B. paratyphosus B” to the organism of paratyphoid fever and nothing else, and of designating the organism that most commonly causes food-poisoning outbreaks as B. aertrycke, and not as B. paratyphosus B (type aertrycke). In view of the fact that the features of a paratyphoid fever outbreak due to infected ice-cream, and of an aertrycke enteritis due to infected pork as occurring in Aberdeen in 1925 emphasise the distinction between paratyphoid fever and aertrycke enteritis, it has seemed well to record these two outbreaks in some detail for the purpose of contrasting them the one with the other and with the milkborne Gaertner enteritis which is recorded in the preceding paper.

1. In the absence of the epidemic prevalence of the dysenteries over a period of 30 months it is found that cases of the various forms of dysentery as occurring in Aberdeen have been in the proportion of 1 amoebic, to 3 Flexner, to 6 Sonne dysenteries, and it is concluded that B. dysenteriae Sonne is the most frequent cause of dysenteric outbreaks in Aberdeen in non-epidemic times.

2. A description of the clinical and bacteriological features of Sonne dysentery is submitted.

3. Preliminary experiments, undertaken with a view to ascertaining whether B. dysenteriae Sonne produces a true exo-toxin, are described.

The foregoing report of Professor van Loghem and his co-worker, Miss Benjamins, confirms the results found by Professor Beattie and Dr Lewis, concerning the bactericidal action in milk of the electric current of high voltage. It also proves that the sterilising power of electrical treatment with carbon electrodes is not inferior to that with copper electrodes. These results, and also my experience of the vitamin C sparing effect of the carbon electrodes, have caused me to recommend the use of this kind of electrode in the electric treatment of milk, provided that the milk used be fresh and that it contains but little oxygen. The same reservation applies to milk pasteurised by heat and to pure raw certified milk. It is important that the supply should be fresh.