The experiments recorded in this paper were undertaken in order to ascertain the effects of certain dyes and allied organic compounds on three selected species of bacteria, Staphylococcus aureus, B. coli and B. pyocyaneus. These experiments show that in cultures the results are influenced by many factors, and appear to suggest that the varying results of the use of these compounds in the treatment of wounds may be ascribed to some extent to the different conditions prevailing in each case.

(1) The antiseptic and bactericidal properties of Flavines and Brilliant Green. Extended investigations have confirmed the original values. It has been shown that the inferior potencies recorded by certain other workers depend on the use of methods unsuited for the observation of antiseptic properties, i.e. they fail to detect inhibition of bacterial activity i.e. bacteriostatic action, which is exhibited to a marked degree by flavine and brilliant green.

(2) For the therapy of a local bacterial infection, as in a wound, such bacteriostatic action is of great value. It is not essential that the chemical agent should by itself actually kill the organisms. Highly successful results can be obtained by a co-operation of the antiseptic and the tissues, so that the pathogenic action of the organisms is restrained. The flavines in virtue of their low toxicity to mammalian tissues and their high bacteriostatic power are therefore specially suited to act as local therapeutic agents. In addition, the fact that they are not neutralised by admixture with serum enables them to be applied clinically by a relatively simple method which does not necessitate frequent renewal.

(3) The “fundamental error” to which the method of testing chlorine antiseptics originally practised by Dakin, is liable, and which Dakin and Dunham have drawn attention to, has been shown not to affect our previous results with Chloramine-T. The difference between our values and the others is due to the fact that we employed 80 per cent. serum in the test.medium, which is much more active in neutralising this antiseptic than is 33 to 50 per cent. serum employed by Dakin and his co-workers.

1. Investigation by American bactriologists have shown that the lactose-fermenting (gas-producing) bacilli can be divided into two main types distinguishabel by the methyl-red and Voges-Proskauer reactions.

2. The methyl-red- Voges-Proskauer + type are shwon to be rare in human and animal faeces, more common in surface water, milk and sewage, and the predominant type in soil and grain, and to be more resistant than the methyl-red + Voges-Proskauer-type.

3. Investigations by the author of this paper confirm their findings as regards human and animal faeces, water, milk and grain. An investigation of the types present in soil is being undertaken and it is hoped to publish an account of this later. Already the “M.R.—” type has been found to predominate in four out of six samples of soil.

4. In the present investigation organisms of the “M.R.—” type were found in 66 samples of water out of a total of 200 containing lactose-fermenters, and in 41 samples containing this type no evidence of recent contamination could be adduced by the search for organisms of the “M.R.+” type ofStreptococci. Judgment of the water was therfore liable to modifiction in 20% of these samples by the recognition of this type.

5. Twenty-nineout of the 66 samples containing organisms of the “M.R.—” type were from sources of good repute, most of them from public supplies.

6. The presence of lactose-formenters of the “M.R.—”“V.P.+” type must be regarded with considerable less disfavour than the presence of “M.R.+” “V.P.—” organisms, and the application of tests for the recognition of these types is impotant. It is suggested that these tests should be included in all routine examinations of water and food products.

In conclusion I have pleasue in acknowledging my indebtedness to Dr. W.G.Savage for calling my attention to the reserches of American bacteriologist and for many valuable suggestions he has made in connection with this work.

The Japanese investigators (Inada and Ido) who discovered the Spirochaeta icterohaemorrhagiae, the cause of infectious jaundice, showed that the serum of patients who had recovered from the disease contained immune substances which were capable of destroying the spirochaetes in the blood and tissues of an experimentally infected guinea-pig. They found that if the serum were injected into the guinea-pig prior to the appearance of icterus the disease was inhibited in all cases. The same result was obtained with the serum of immunised goats.

As there appears to be a considerable amount of uncertainty (as evidenced by recent writings on this subject) regarding the biological relationships and the etiological significance of the so-called “atypical B. dysenteriae,” this short communication is intended as a brief résumé of conclusions arrived at in the course of an extended investigation of dysentery bacilli in Egypt during 1916 and 1917. It is to be noted that the results recorded here were obtained from the examination of cases of dysentery observed in the earliest stages and frequently followed into convalescence. Such experience has shown that conclusions derived solely from an investigation of the later stages of the disease, e.g. convalescents examined after arrival from over-seas in the United Kingdom, throw little light on the problem of the bacterial etiology of the disease as a whole. In a paper by Thomson and Mackie (1917) on the clinical and laboratory study of dysentery in Egypt a number of atypical dysentery strains were described, but at the time this communication was submitted for publication my observations were not sufficiently complete to make any general statements regarding organisms of this type and no attempt was made to classify them.

The following contains a preliminary account of the work on the Etiology and Pathology of Trench Fever which has been done at the Lister Institute in connection with the War Office Committee on Trench Fever under the Chairmanship of Major-General Sir David Bruce, F.R.S. A first account from the Clinical side has been published in a paper by Major Byam, R.A.M.C., and his colleagues at the New End Military Hospital, Hampstead, and read before the Society for Tropical Medicine and Hygiene in May of last year. We have been mainly dependent for our material on Major Byam and the rest of the Medical Staff of the New End Hospital and are very much indebted to them for their help and courtesy. We are under an especial obligation to Lieut. Ll. Lloyd, R.A.M.C., who has carried out that part of the entomological work done at the Hospital, taking immense pains in supervision and in obtaining the material which we required.

Owing to some regrettable slips in the arithmetical work of the paper dealing with eye colour and intelligence recently published in this Journal several of the constants are inaccurate. The whole of the calculations have now been re-worked and the correct values are given below. I have incorporated some fresh material, the analysis of which somewhat strengthens the conclusions already published.