1. Dengue Fever in Australia is undoubtedly an introduced disease. It has been existent from time to time in epidemic form since 1885.

2. The clinical description of the disease agrees with that of the Dengue described in text-books, the only departure noted being the distinct tendency to a relatively, and sometimes absolutely, slow pulse rate as compared with the temperature.

3. It is possible that under the single term “Dengue” more than one disease is at present included.

4. Epidemic Dengue in Australia is approximately co-extensive with the known distribution of Stegomyia fasciata. It does not extend beyond the area in which this mosquito is prevalent.

5. Stegomyia fasciata mosquitoes caught in a dengue infected district in the surroundings of cases of the disease, and some of them known to have fed on a dengue patient on the first and second days of his illness, transported to a non-dengue district, reproduced the disease in four out of seven persons on whom biting experiments were conducted.

6. Blood taken from three of these four cases reproduced the disease when injected into further persons. The blood of one case was not tested.

7. The incubation period of the four cases was found to be possibly between five and nine and a half days, probably between six and a half and nine and a half days, counting from the bitings to the definite onsets.

8. No known case of contagion occurred from any of the above four cases.

9. No evidence was obtained from two cases, one of which was heavily and repeatedly bitten with Culex fatigans, that Culex fatigans is capable of acting as a transmitter of dengue fever.

10. The blood of patients suffering from an attack of dengue can reproduce the disease when inoculated subcutaneously into healthy persons.

11. The disease thus inoculated is typical in every way of dengue fever naturally contracted. The inoculated disease may or may not shew marked skin rashes and double phases in the temperature charts, and presents a relatively and sometimes absolutely slow pulse; such variations occur in the natural disease. The incubation period of the inoculated disease varies from five to nine days corresponding with the incubation period of the mosquito-transmitted disease.

12. Results of the inoculations shew that:

(a) The virus of dengue is present in the blood as a whole.

(b) The serum of clotted infective blood may contain the virus.

(c) With washed corpuscles one apparently positive result was obtained out of three experiments.

(d) The fluid part of citrated infective blood may contain the virus.

(e) With Pasteur-Chamberland filtrates of infected serum and corpuscles, one positive result was obtained out of five experiments.

In considering these results failure to convey tne disease must not necessarily be interpreted as meaning that the menstruum employed never does contain the virus, as in some of the cases the blood may no longer have been infective at the time at which it was withdrawn.

(f) The presence of the virus in the blood has been demonstrated on the second and third days of the disease. Two experiments made may possibly be interpreted as shewing that infective material may still be present on the eighth day of the disease.

(g) One experiment appears to indicate that the virus is no longer present in the blood on the fourteenth day from' the beginning of the illness.

(h) Immunity to the inoculation of infective blood appears to be complete twenty-four days after recovery from a typical attack of dengue.

(i) Infected blood may maintain its infectivity outside the body if kept in a cool place for seven days at least.

(j) In two instances two individuals inoculated with the same material on the same day exhibited incubation periods practically identical in duration.

(k) The infection of dengue can be conveyed by sub-inoculations from individual to individual at least to the fourth generation without the resultant disease departing from the type of the natural disease.

(I) The disease has not been conveyed by the application of infective serum to a scarified area; nor apparently has it been conveyed by the application of infective material by swabbing to the nostrils.

(m) A very doubtful and probably negative result followed the gargling of the throat with infective material followed by swallowing of the same.

(n) Dengue fever has close analogies with yellow fever.

Temperature has a profound influence on the rate at which changes appear in a carcase. A very low temperature indefinitely postpones the apparent changes.

The optimum temperature seems to coincide with that which is most suitable to the activities of ferments and bacteria present in the living body. Alterations in temperature, such as occur in exposed carcases, during the day and night, probably influence putrefaction by their effects on bacterial activity, antagonism, and symbiosis. Variations in temperature conditions may produce changes more profound than would appear likely on superficial consideration. The optimum temperature for one group of organisms is different from the optimum conditions for another. Changes in temperature, therefore, especially if they are of some duration, are apt to favour some groups at the expense of others, and influence in this way the whole sequence of subsequent events.

Water is necessary to the growth of bacteria. It permits of their migration in the tissues, allows their ferments to act, distributes by diffusion the substances on which they live, and dilutes the toxic products of their activity.

The effects of temperature and moisture cannot be dissociated for it is in combination that these factors exert their greatest influence.

In a hot dry atmosphere the removal of water by evaporation may be so rapid that a small carcase may become desiccated before putrefaction has advanced far. In hot arid countries a variety of influences inimical to putrefaction are at work, especially when carcases are resting on dry sand. The strong sunlight tends to destroy the skin organisms, which we believe to be the most important agents in producing putrefaction. The skin soon becomes horny in consistency, imprisoning the organisms within it, and preventing their invasion of the tissues. The horny skin protects the carcases from moisture from any source, and the exudation of fluid finally results in mummification.

In a hot moist atmosphere sunlight is robbed of much of its bactericidal power, and the conditions most favourable to putrefaction prevail. Moisture from the air, rain water and water from the ground are absorbed and keep the skin moist. Suitable conditions for the growth and penetration of skin and soil organisms are thus created. Very soon the superficial layers of the epidermis are loosened and the sodden skin permits the autolytic enzymes, passing from the deeper parts, to exert their action on it and assist the putrefactive organisms. The aerobic conditions now prevailing in the skin aid disintegration. The protective influence of the skin is thus lost, and water has free access to the underlying tissues, where it exerts its elutriating and solvent effects. The products of putrefaction are diluted and removed and the dissemination of organisms favoured. Oxidation now plays some part in the process and disintegration proceeds rapidly. The presence of maggots seems to hasten putrefaction.

Such considerations ought to be sufficient to suggest the inadvisability of treating decomposing animal matter with watery solutions of antiseptics as is so often done. Here we may point out that the flesh can be completely macerated from the bones in six days, if a carcase is kept in water at 37° F. The progress is especially rapid, if the water is changed after three days, and the products which seem to inhibit bacterial growth removed.

Within a few days of death, the time varying with the conditions, certain phenomena are noticed if a carcase is kept under observation. It becomes distended with gas, fluid exudes from it, and the skin over certain areas becomes green. These phenomena are usually regarded as evidences of putrefaction. Since in properly treated carcases they are not followed by disintegration of the proteins, which form the main constituents of the body, and since they appear to be due partly to enzyme action and partly to the action of intestinal bacteria of the colon-type on such constituents as carbohydrates, and not to the action of putrefactive organisms, we consider that we are justified in regarding these phenomena as precursors of true putrefactive changes. By the latter term we understand the disintegration of the tissues by putrefactive organisms, a process accompanied by the elimination of foul-smelling products.

The evidence on which this conclusion is based has been given in detail in this section, and here we propose to discuss only the more important considerations.

The experiments with individual strains in sterile water show a marked difference between the behaviour of the streptococci and B. coli. In all cases the streptococci diminished in numbers and in two experiments were practically eliminated at the end of 2 weeks while in the other two they did not survive very much longer. On the other hand the B. coli strains although in a medium which contained little or no organic matter, and which was not in any sense a nutrient medium, showed in every case multiplication, in most extensive multiplication. This was rather contrary to our anticipations as although we were prepared for prolonged survival under conditions of freedom from com peting bacteria we did not anticipate such marked increase in numbers. In Exp. XIX the bacillus tested was still present over fifty-fold of the original number at the end of 11 weeks.

We have given some attention to the characters of the surviving types of B. coli in the tank experiments. Generally speaking they were quite normal in respect of fermentation reactions but on three occasions, Exps. XIII, XV and XX, the capsulated “high ratio” (CO2: H) coli of Clark and Lubbs were found, and in Exps. IV, XX and XXI the surviving organisms isolated were also capsulated but not “high ratio” organisms. It appears possible that the capacity to form capsules has something to do with the viability of these organisms and Exps. XXII and XXIV are evidence in this direction, but it is to be noted that the surviving B. coli in Exp. XVI after 7 weeks produced no definite capsule when grown in milk.

In Exp. XX the original sewage was plated out upon lactose neutral red bile salt agar and 10 strains of B. coli isolated of which 50 per cent, showed capsule formation. Fourteen days later 11 strains were isolated from the sewage tank water and of these 90 per cent, were weak lactose fermenters and showed no capsule formation. In the same experiment 2 strains isolated after 4 weeks and another after 5 weeks showed definite capsule formation. The ultimate B. coli survivors were a pparently all capsulated organisms, although at the start as many non-capsulated as capsula ted organisms were present.

The tank experiments with excreta or sewage added to a large bulk of water yielded minor differences in the individual experiments, but in general they all show a rapid diminution and elimination of the streptococci and a continuous but not quite so rapid diminution inthe number of B. coli. With the latter it was more common to find persistence in small numbers for a period extending to many weeks. The elimination of the streptococci was particularly uniform and rapid. At the end of 2 weeks in only one experiment were they present in more than insignificant numbers.

While the diminutioji was rather more rapid for excreta than for sewage for both streptococci and B. coli, no definite constant differences in relation to the kind of contamination could be made out.

The decline curves of both organisms agree very closely as can be most readily seen if the figures are plotted out as graphs. Three of the experiments, in which the initial numbers of B. coli and streptococci were identical, and also Exp. XI are set out in this way.

The available data is hardly extensive enough to enable deductions to be drawn other than broad and general ones, but the facts add confirmation to the view that the presence of either streptococci or B. coli in considerable numbers, i.e. in 1 or even 10 c.c. of a water, can only indicate contamination considerable in amount and of recent origin.

In particular the finding of streptococci in any numbers can be accepted as indicating considerable and recent contamination. We consider that the streptococcus determination is very valuable on its positive side as an indication of recent contamination. As a means of judging of the recency of the contamination it is even more valuable than the B. coli enumeration.

Put another way our experimental data shows that in nearly every case there is a marked diminution in the number of both B. coli and streptococci at the end of even 1 week, so that it.follows that when these organisms are found in large numbers the contamination must have been either very recent or especially abundant.

1. 52·6% of marmots placed in contact with marmots infected with plague by inhalation developed pulmonary plague and died within 4–6 days.

2. Marmots suffering from pneumonic plague are infective at an early stage of the disease and the animals which such marmots infect acquire plague after a short incubative period.

3. Pulmonary plague can be readily transmitted to the small marmot (Spermophilus citellus Linn.), and these animals, when suffering from pulmonary plague, are in turn capable of transmitting the same type of plague through the respiratory passages.

4. Septicaemic plague can be developed in marmots very easily as a result of respiratory infection and also by direct subcutaneous inoculation with small amounts of culture.

5. The marmot can acquire plague by way of the alimentary tract and spread the disease by feeding on plague-infected carcases. The histological appearances observed in the lesions of these cases are characteristic.

We have already considered, in previous papers, the influence of parental age, on birth, marriage, sex, susceptibility, and reaction to bacterial invasion, evidence having been produced which lends support to the belief that this factor does modify the organism in its behaviour with respect to the attributes considered. It is therefore reasonable to extend the enquiry, and examine whether these variations are accompanied by modifications in structural attributes. In the present paper the characters studied are, eye-colour, stature and intelligence.

Bile is often referred to as if its chemical composition was constant and that by treating samples of bile with extractives similar results would be obtained, whereas samples of human bile differ to such an extent that the term bile in itself signifies little. Two samples of human bile may differ to such an extent that while one sample has the qualities of true bile as regards its bile salt content the other may be entirely devoid of lytic action on red blood cells. Numerous experiments made with human bile obtained during life and from the post mortem room have shown this to be correct. The actual bile salt content of bile can be judged by boiling the bile to remove much of the protein, and also to destroy bacterial activity and then contrast the haemolytic activity of the treated sample with a 1 per cent, solution of bile salt in normal saline.

We were recently consulted by an officer serving on the Western Front as to the significance attaching to ordinary bacteriological methods of gauging the potability of waters. He wished to know what was the probability that a given water supply did not contain more than a certain proportion of bacteria in the unit volume, it having been found that particular samples tested showed no growth while, perhaps, larger samples had done so, or that so many out of a series of samples of the same size had given positive results. Having obtained what seemed to us a reasonable solution of the particular problem proposed, we thought that the results might interest other officers and bacteriologists who have to do similar work. A survey of the criteria actually used by bacteriologists when they form an opinion as to the purity of waters seems to us to emphasise the need for some discussion.

In twenty-five consecutive cases in which nasopharyngeal cultures have been made from patients suffering from bacteriologically proved cerebro-spinal meningitis, meningococci have been obtained.

A striking similarity between the organisms from the two sites has been shown to exist for not only are they of the same agglutinable type but in the majority of instances individual peculiarities of agglutination have corresponded. The closeness of relation has been further demonstrated by the carbohydrate reaction in one case in which the unusual property of bleaching glucose litmus broth to a yellow colour was possessed by both organisms. Nevertheless, in a certain number of instances, though organisms of a different agglutinable type have not been isolated, as by other workers, there have been found certain minor variations of agglutination. That most if not all of these variations are due to alteration of the agglutinable capacity of one of the organisms seems probable, as in the six cases where most marked difference existed (Nos. 1, 3 and 24 of Type I and Nos. 15, 16 and 18 of Type II) the chances of the other alternative, namely that a second infection had happened in each case to be of the same agglutinable type, are remote.

In the twenty-five cases the proportion of the types present has been shown to agree with that found by other workers during the same period. Seven of the infections (28 per cent.) have been due to Type I and eighteen (72 per cent.) to Type II.

Ten of the cases have occurred in children under the age of two years, and the proportion of the two types among them has been approximately the same as among older patients.

The writer is indebted to the members of the staff of St Bartholomew's Hospital for permission to publish their cases, and gratefully acknowledges the encouragement and assistance of Professor Andrewes at whose instigation these investigations were conducted.

1. Of 123 dysentery bacilli isolated, forty-seven were B. dysenteriae Shiga, seventy-six were mannite fermenters.

2. The biochemical activities of forty-nine strains of the latter were investigated immediately after isolation and again six months later. They showed variability as regards the fermentation of maltose, saccharose, dextrin, raffinose, arabinose, isodulcite, sorbite and glycerin and in the formation of indol. The same strain varied at different times, some gaining, others losing one or other of the above properties.

Similar observations by other observers and the authors are discussed and the conclusion is arrived at that the separation of the mannite fermenting dysentery bacilli into groups on the ground of their action upon the above carbohydrates is unsound and that the only carbo-hydrates of service for their identification are glucose, mannite, lactose and dulcite.

3. An experiment conducted during two and a half months upon a particular strain of dysentery bacillus shows that the fermentation of saccharose was in this strain a “recessive character” and only maintained by artificial selection.

4. One-sixth of the mannite fermenting dysentery organisms isolated were not agglutinated by a univalent Y (rabbit's) serum at the time of isolation but half of these acquired this property by cultivation. Others were well agglutinated by the patient's serum. An experiment is described in which agglutinability to Y serum was lost under prolonged cultivation on saccharose peptone media. In this experiment successive cultures were made every few days and the material for subcultivation was taken from daughter colonies (buds), which arose in the saccharose plates. Agglutinability was rapidly regained by propagation in broth. From the author's experience and from a survey of the literature, the conclusion is arrived at that no one univalent serum will agglutinate all dysentery bacilli of the mannite fermenting type and that a bacillus with the morphological, cultural, and biochemical characters of dysentery bacilli of this type is not discredited as an etiological factor because it is not agglutinated by any particular univalent serum.

In conclusion we express our indebtedness to Miss Rhodes of the Lister Institute for retesting many of the cultures in London, in January, 1917, and convey to her our grateful appreciation of her kindness in so doing.

The results obtained point to a consistent relationship between lipolytic activity and bacteriolytic power on tubercle bacilli.

The least bactericidal extract was lung extract; the most powerful was pancreas extract.

Liver, thymus and lymphatic glands were strongly bactericidal.

Other organs, suprarenal glands, pig and cat spleen, human and cat kidney, human and ox brain, ox thyroid, cat lung, ox bone marrow and ox pituitary glands were found to be bactericidal to a lesser degree.

The human skin extract examined for bactericidal properties was fatty and cloudy in appearance and exceptionally rich in esterases1.

Even if exceptional in its esterase activity this sample of skin bears out the relationship between lipolysis and bacteriolysis of tubercle bacilli in a striking way, as it was also extremely bactericidal.

No difference was noticed between bovine and human tubercle bacilli in susceptibility to any gland extract examined.

Other acid-fast bacilli, though on the whole less susceptible than tubercle bacilli to the influence of these extracts, were bacteriolysed by them. They were also killed by one lung extract (pig's) which contained an unusually large amount of olein lipase and which had no effect on tubercle bacilli.

I wish to express my thanks to Dr W. Cramer for his kind advice and encouragement, to Dr Cobbett for his kindly criticism, to Professor Shennan and Dr Miller for human material, and to Dr Wang for several strains of tubercle bacilli.

The expenses of this Research were met in part by a grant from the Earl of Moray Trust.

It was desired to determine the minimum amount of acid which would kill tubercle and other acid-fast bacilli, incidentally to note any distinction between human and bovine tubercle bacilli and between tubercle and other acid-fast bacilli in respect to sensitiveness to acid, and to find whether inorganic acid were more powerful in action than organic acid, and whether insoluble fatty acids were also effective.

“White Australia,” the pleasant dream of a peculiar political party, is a subject on which a few years ago it would have been inadvisable if not unsafe to venture too unrestrained opinions. There was a time when in certain quarters the euphonious phrase was almost tantamount to a war cry. To some political dreamers it may even have been a perennial dream, full of visions of whiteness and purity, just as to us in England the mention of the “Pearly Pacific” conjures up vistas of prattling palms, wimpling waters and silvery strands. The dream is a pretty one, fitting theme for the poet and artist; Samoa and R. L. Stevenson, what a perfect juxtaposition! What delectable tales our romance weavers indulge us with! The gorgeous colouring, the wondrous life, the glorious moon, the ocean's unceasing sigh—all fine, all beautiful, all seeming perfect—but all superficial or tempered with prosaic features which mar the picture.

In the preceding reports on infant mortality in counties during 1908 (Cd. 5263), in 241 urban areas in 1907–10 (Cd. 6909), and in Lancashire (Cd. 7511), the chief environmental circumstances favouring excessive infant mortality have been enumerated and to some extent discussed.