In torrid regions, thermal environment is of very great importance as regards comfort and certainly influences the health and efficiency of white men. The human race may have arisen under the influence of climates similar to those now prevailing in the Tropics where indigenous peoples sojourn in an almost natural state with little protection against either heat or cold. The European brings with him his native conventions as regards houses and clothing, developed, in the case of Britons, in quite northern regions, where the human race requires protection against cold. These may be more or less unsuitable for tropical heat but, being conventions, they cannot be lightly thrown aside. European clothes afford protection against disease-carrying insects, poisonous stings and bites, and the question arises as to the best way to modify them to suit the hot climate. In any case, the northern European in the Tropics is in an abnormal climatic environment and, though he may survive a long time, there can be little doubt that he rarely enjoys his natural robustness of health with the result that even trivial ailments assume serious aspects. It appears that there is a much narrower margin of health stability, and proportionately greater care is required if the system is to be kept within the limits. Mr Elsworth Huntingdon1 has adduced evidence suggesting that white races, even if they are able to survive within the torrid zone, undergo deterioration.

The purpose of this paper is to place on record the available figures relating to cases of tetanus which occurred in Home Military Hospitals during the Great War of 1914–1918. It may be considered that some of the tables give no very useful or practical information, but they are nevertheless recorded in order that medical officers at the outbreak of some future war may have the opportunity of learning what was done for the prevention and treatment of tetanus during this war. For example nothing can be gained from a study of the figures given in this analysis with regard to the curative or therapeutic value of antitetanic serum, but it may be of some antiquarian interest half a century hence to know the amount given and the mode of administration in the years 1914–1918.

One of the main postulates, upon which Dreyer's system for agglutination- tests is based, is that no two suspensions of any organism can be taken as identical in agglutinability. This fact is now too well proven to need further demonstration, though it is still disregarded in many a current method.

1. In dilute neutral meat extract cultures (without salt or peptone) inoculated with relatively small numbers of S. aureus, taken from agar cultures grown for 18 hours at 37° C. and incubated at 37° C., multiplication proceeds rapidly during the first day and more slowly on the second, when the maximum number, about 10,000,000 per standard loop (0·01 c.c.), is reached. Later the number of living organisms decreases at first rapidly, but later more slowly, until a low level is reached, which remains fairly constant or falls very slowly for a long period. During the period of relative constancy small oscillations are observed. The curve produced on plotting out the daily counts may be regarded as a “standard.”

2. The frequency with which the culture used for inoculation has been transplanted on agar slopes influences the growth on neutral meat extract. Several transplantations in rapid succession result in very rapid growth, a high maximum and a very rapid fall in the numbers. Less frequent transplantation over a long period seems to cause the maximum to be reached later than in the standard and the period of decline to be postponed.

3. In one series of experiments (Section III) the proportion of meat extract was varied in the different tubes employed. These experiments show that the greater the proportion of meat extract the greater is the multiplication, and the longer the period which elapses before the curve reaches its highest point, in fact the extent of multiplication appears to be closely related to the amount of meat extract present in the culture. The length of the period of rapid decline is also related to the amount of meat extract present.

4. The form of the curve of growth is influenced by the number of cocciinoculated. With a small inoculation into dilute neutral meat extract the maximum number of cocci present in the medium at any period does not usually exceed 10 to 12 millions per standard loop. If the initial dose greatly exceeds this figure multiplication proceeds relatively slowly for two days and subsequently there is a very rapid fall in the numbers. With an initial dose close to this figure a somewhat similar curve is produced, though the rate of fall is not so rapid. Much smaller doses produce “standard” types of curves.

5. Provided the numbers inoculated are small (50,000–50 per drop) the results after 24 hours' incubation in different experiments of the same kind are not materially affected.

6. If after the numbers have reached a low level small drops of concentrated meat extract, insufficient to cause appreciable dilution, are added to the culture further multiplication occurs, to some extent proportional to the amount of food material added. The fall in numbers, which follows the initial rise, is not due therefore to the accumulation of products, but seems to be caused mainly by the using up of food material.

7. By small regular additions of food material (concentrated meat extract) a definite concentration of Staphylococci can be maintained in a meat extract medium for a long period of time, and probably by suitable additions any desired concentration could be maintained. Accumulation of the products may gradually inhibit growth, but on this point the experiment gives little evidence.

8. Moderate dilution with distilled water at any stage of incubation has little effect. Events occur in the usual sequence, but the number of organisms in each standard drop is proportional to the dilution.

9. The incubation temperature has a great influence on the course of events in meat extract cultures of S. aureus. At 37° C. multiplication during the first 24 hours is very rapid, the maximum is attained on the second or third day, and the numbers fall very rapidly. At 27° C. the maximum is attained on the fifth or sixth day, and is considerably greater than that attained at 37° C. The fall is rapid. At 17° C. multiplication is very slow during the first 48 hours, but is subsequently rapid, and the maximum, which is higher than that attained at 27° C., is reached on the eighth day. The decline in numbers is slow.

At 8 to 10° C. very slight multiplication, if any, occurs during the first 24 hours and subsequently the numbers steadily decline for at least 60 days.

At lower temperatures the numbers fall rapidly and the cultures die. At — 1° C. the organisms were dead by the 19th day, at — 6° C. by the 13th day, and at — 10° C. by the 9th day.

10. If organisms such as S. aureus, B. coli or B. pyocyaneus are allowed to grow in meat extract medium at 37° C. until the numbers have reached a low level, and the tubes are then inoculated with the species originally present little or no multiplication takes place, but if one of the other organisms is inoculated multiplication of the added organisms occurs. If the cultures are sterilised by boiling before inoculation with fresh organisms the original strain or the others, when added, multiply. Boiling, therefore, appears to liberate some food for added organisms belonging to the strain which was originally present.

The growth of any of these organisms in the medium seems to remove most of the food for that species as well as a portion of the food substance used by other species, since in no case was the growth of the added species nearly so considerable in extent as in its primary cultures.

11. The effect of adding increasing quantities of N/10 hydrochloric acid up to 0·3 c.c. to each 5 c.c. of the medium is to retard the growth of the cocci during the earlier stages of incubation, though subsequently rapid growth takes place, and a high maximum is reached. With small inoculations of cocci the addition of more than 0·3 c.c. N/10 hydrochloric acid results in the death of the organisms within a short time.

With additions of N/10 soda varying between 0·4 and 1·2 c.c. there seems to be a progressive decrease in the height reached by the maxima, the rate of growth in the early stages is retarded, and the rate of decrease in numbers seems to be retarded. With the addition of 1·6 or 1·8 c.c. N/10 soda the rate of growth in the early stages is markedly retarded. With the addition of 2·0 c.c. N/10 soda no growth occurs.

B. coli seems to be more sensitive than S. aureus, especially to the addition of alkali.

12. More precise experiments with N/10 hydrochloric acid show that with the addition of increasing amounts of the acid the type of curve gradually changes from a “standard” with one peak to a curve with two peaks, separated by an interval in which the numbers are small.

13. By continuous growth in acid, neutral and alkaline meat extract the capacity of S. aureus to multiply when transplanted into media of different reactions is altered. When transferred into an acid medium all strains show a small primary rise followed, after a fall in the numbers, by a great secondary rise. In the case of the acid acclimatised cocci the secondary rise reached its maximum on the 7th day, in the neutral acclimatised cocci on the 13th day, and in the alkali acclimatised cocci on the 15th day. In the neutral medium there is also a primary and a secondary rise, but the former is much greater than the latter. In the case of the acid acclimatised cocci the primary rise was least in height and duration, and in the case of the alkali acclimatised cocci greatest both in height and duration. In the alkaline medium a primary rise only occurs and subsequently the numbers fall to a very low level. The rise was least in the acid acclimatised cocci and greatest in the alkali acclimatised cocci.

In comparing these experiments with others previously quoted it should be remembered that the organisms have been acclimatised to growth not only in media of different reactions, but also to continuous growth in fluid meat extract medium.

14. S. aureus can multiply to a small extent in neutral gelatin solution (8 per cent.). On a medium consisting of gelatin and meat extract the greatest multiplication takes place, much higher figures being obtained than the maxima of growth on gelatin solution and meat extract respectively added together. In agar solution (0·8 per cent.) also no multiplication takes place, and the cocci quickly die. In a medium consisting of agar and meat extract the maximum reached is lower than in meat extract, but the decline in numbers is slower.

15. When certain quantities of various acids are added to warm meat extract agar precipitates are formed, though little or no precipitate may be produced by lesser or even slightly greater quantities. In some instances no growth occurred in plates poured from those tubes in which a precipitate had formed.

16. The addition of glucose to the extent of 1 per cent. to dilute meat extract results in most cases in S. aureus multiplying rapidly during the first day. Subsequently the numbers decline and the culture dies. With increasing quantities of glucose the maximum figure attained diminishes, and the rate of the subsequent fall, at least from the second to the fourth day, increases. Even with a very small quantity of glucose the numbers begin to fall after 24 hours's incubation, instead of rising as they do in cultures without glucose.

If to cultures containing 1 per cent. glucose daily additions of small quantities of concentrated meat extract or of concentrated meat extract with glucose are made oscillations in the numbers occur, but the cultures remain alive and with large additions multiplication may take place. The death of the organisms is not hastened by small daily additions of glucose.

17. The addition at different times of small numbers of the cocci to growing cultures of S. aureus has no appreciable influence, but the addition of large numbers exerts a considerable influence.

18. In meat extract cultures of S. aureus incubated at 37° C. about 15 per cent. of the living organisms sink to the bottom after each daily shaking. If the tubes are left undisturbed about 25 per cent. sink to the bottom.

19. Meat extract incubated with chloroform for 24 hours at 37° C. and sterilised by boiling seems to be a slightly better medium than fresh meat extract sterilised by boiling or autoclaving immediately after preparation. Pancreas extract is a better medium than meat extract. The multiplication of cocci is greatest in pancreas extract incubated with chloroform for 24 hours at 37° C. and sterilised by boiling.

20. Organisms accidentally contaminating cultures of S. aureus may cause, according to their species, a sudden decline or a rapid increase in the number of the cocci.

In analysing some samples of air which had been sent for examination, the writer was struck by the presence of an altogether abnormal quantity of carbon dioxide associated with a very much diminished oxygen content. In view of this excess, the space from which these samples had been obtained was then thoroughly ventilated and after remaining closed for only four days the air was found to contain already 2·27 p.c. of carbon dioxide instead of the normal 0·03 p.c. No immediate explanation of the phenomenon was available and this paper contains a short account of the research made to discover the cause.

The following information in regard to the distribution of malaria in South Africa has been compiled chiefly from the reports of Government Medical Officers and Health Officials who were circularised by courtesy of the Union Public Health Department in March, 1918, in regard to the following points:

(1) The areas affected in each district.

(2) The type or types of malaria existing.

(3) The incidence of the disease, whether endemic or epidemic; and

(4) The types of anopheline mosquitoes identified.

The information available from these sources indicates the necessity for a considerable amount of further work to provide a more complete and accurate knowledge of the incidence of malaria in South Africa.

With regard to the influence of malarial infection on the Wassermann test some controversy prevails:

Wassermann and Lange (1913) refer to Meyer and Bonfiglio who, working in Italy, obtained a positive reaction in 80 per cent. of the cases where the blood contained parasites; in some of their cases positive reactions were obtainable for several months after the disappearance of fever and parasites. For this reason Wassermann and Lange advise to put every case, coming from a malaria-infected country and showing a positive reaction, under quinine treatment and to repeat the test after a lapse of six weeks.

The work on the meningococcus described in this report was begun in 1916 in connection with the measures instituted by Lieut.-Colonel M. H. Gordon, C.M.G., for the preventive control of cerebro-spinal fever in the Army.

The chief facts learnt from these investigations on blackwater fever are summarised briefly here in the order in which they are detailed in the sections.

1. True jaundice, due to the presence of bile pigment in the plasma, occurred in a high percentage of the cases which ended fatally. Haemoglobinaemia, varying from a deep red coloration of the plasma to a faint tinging, occurred in the acute stages of the disease. There was no evidence of auto-agglutination or auto-haemolysis. The fragility of the red cells was unaltered. No relationship between syphilis and blackwater fever was obtained. Spirochaetes were not demonstrated in the blood in any instance. In the hundred cases in this series, a malarial history was obtained in every instance, and without exception the infection was contracted in the Balkans during 1915–1918. The only blood parasites found were Plasmodium vivax and Plasmodium falciparum.

2. The most important tissue changes were as follows: Fatty degeneration of the myocardium. Reduction of the fat lipoid content of the adrenal gland. Enlargement of the Malpighian corpuscles of the spleen due to various changes in the endothelial centres. Recent or chronic perisplenitis was present in every instance. The other changes in the spleen were numerous and variable and due to blood destruction and malaria. Haemorrhages in the liver tissue and foci of central necrosis, in which reactionary changes had occurred, were met with in many instances. Inspissation of the bile in the gall bladder and bile passages was of common occurrence.

The changes in the kidneys during the acute stages of blackwater fever were very pronounced, but complete recovery rapidly ensued during the period of convalescence without subsequent nephritis as far as the information available indicated. Spirochaetes were not found in any of the tissues in this disease. Scattered haemorrhages occurred in the most rapidly fatal cases.

3. From alcoholic and acetone extracts of the dried residue of the urine, obtained during the period of haemoglobinuria, haemolytic substances were demonstrated. From alcoholic and acetone extracts of the dried organs very active haemolytic substances were obtained, more especially from the acetone extracts.

The alcoholic extracts of the urine were more potent than the acetone in the three cases which recovered. Similar results were not obtained by extracting the dried viscera from cases other than blackwater fever, including malaria.

4. There was no evidence that quinine administered by any method during an attack of blackwater fever increased the severity or influenced the progress of the disease apart from its eftects on malaria. Quinine administered to animals rendered anaemic did not excite haemoglobinaemia. Quinine was obtained from the urine by extraction, during the period of haemoglobinuria, in amounts which corresponded to those obtained in the malarial cases. Rabbits injected with quinine previous to and during the period when both ureters were ligatured failed to develop haemoglobinaemia or haemoglobinuria.

5. The urine in cases of blackwater fever rapidly returns to the normal from the period of haemoglobinuria. Clumps of red cells which possess certain characteristics were found in the urine in some cases. Clumps of red cells were of common occurrence in the tubules of the kidneys. The injection of sterilised urine from cases of blackwater fever obtained during the period of haemoglobinuria failed to produce any ill eftects in animals.

6. Blackwater fever was most frequently met with during the months of March and April, at the time when the temperature was at the commencement of its upward summer rise. No evidence was obtained that blackwater fever is in any way related to anaphylaxis. It was not possible to employ any method to demonstrate whether blackwater fever is due to a filter passer.

The results so far obtained have raised many questions and answered few of them. The important rôle played in the spread of epidemic disease by the re-accumulation of a susceptible population is clearly indicated. It seems not unreasonable to hope that valuable information as to the effect produced by variations in the rate of such re-accumulation, and on other matters, may be obtained by the satisfying method of direct experiment. The bearing of such information on the well-known fluctuations in the incidence of epidemic diseases, and especially perhaps of those which fall most heavily on children, are too obvious to need emphasising.

The following conclusions seem permissible at the present stage:

(1) If susceptible mice be continuously added to an infected population the spread of infection will continue over a long period of time. There is no evidence that this period has a limit.

(2) When susceptible mice are added continuously and at a constant rate to an infected population, the spread of infection, as judged by a mortality curve, is propagated in regularly recurring waves. These waves are most easily observed by noting the fluctutations in the total cage-population. It seems probable that the period of these fluctuations will be found to depend on the rate of addition of susceptible individuals, but this point has still to be determined.

(3) The actual deaths may occur in large groups, with intervals during which deaths are few and far between, or they may fall in a succession of smaller groups, increasing and diminishing in size to form the larger waves. In all cases there is this tendency for the occurrence of such small groups of deaths with definite maximal points. There would seem to be two fluctuating processes, the one superimposed upon the other.

(4) The average survival-time of mice added to the cage, and their chance of ultimate survival if no more susceptible mice are introduced, vary according to the phase at which they are added. If they gain entrance to the cage during the rise of a wave they are unlikely to live for long. If they are introduced during the fall of a wave their chances of survival are greatly increased, and they will usually outlive mice which are added at a later date but at a time before the commencement of the next wave.

(5) The rate of extinction of a population, among which infection is actively spreading, will be far less rapid if they are kept isolated, than if further susceptible individuals continuously gain access to them. A proportion of the infected population, which would have survived indefinitely under the former circumstances, will die under the latter.

(6) The ultimate survivors among such a population have not escaped infection, but have successfully resisted it. A considerable proportion of them are harbouring the causative parasite in their tissues.

My sincere thanks are due to my colleagues, Dr H. B. Weir and Dr G. S. Wilson, for their constant help, and to Mrs Phyllis Worthington whose assistance in this work I have been able to obtain by the aid of the Medical Research Council.

The large red Oriental Hornet (Vespa orientalis Fabr.) must be extremely familiar to all who served in Mesopotamia. The Rev. F. D. Morice, who has been good enough to identify my specimens, tells me that it can barely be distinguished from Vespa crabro L., the European hornet, except by its colour. It is widely distributed in the Mediterranean countries up to lat. 47° N. and occurs S. to Abyssinia and Madagascar, E. to India, and also as an introduced species in certain parts of S. America.

1. There are fats which are indispensable for children because they contain specific bodies, essential for normal growth.

2. If these lipoid bodies, termed “fat soluble A bodies” by McCollum, are absent from the food for a long time, an inhibition of growth will occur and the conditions which I have termed Dystrophia alipogenetica will finally appear. This condition involves a great susceptibility and lowered resistance to all infections and often leads to xerosis of the conjunctivae and corneae associated with night blindness. The xerosis has a great tendency to result in keratomalacia. In its first stage xerophthalmia resembles a slight conjunctivitis; the children develop photophobia, their eyes are red and there is a slight secretion.

3. Xerophthalmia generally occurs in spring, the time when growth is at its maximum.

4. The disease is most frequent amongst the children of the poorest country folk and is always due to an unsuitable artificial diet, generally the replacing of whole milk partly or completely by centrifuged milk, butter milk or concoctions of flour. It may appear in children who have received whole milk and cream, but in that case the milk and cream have been boiled for too long a time or have been subjected to other kinds of drastic treatment which have destroyed the specific lipoid bodies.

5. Xerophthalmia is easily when recognised in time. The best treatment is cod liver oil, but whole milk and probably cream, butter, eggs and other fats containing the specific lipoid bodies are also curative. It is important to remember that these foods should only be subjected to the ordinary short boiling.

6. The disease is fairly common in Denmark, apparently more so than in other countries. It is, for instance, practically unknown in Sweden and Norway. According to Mori's statistics it used to be rare in Germany. The reason for its being so frequent in Denmark is probably partly due to the fact that this country exports most of its dairy produce, especially butter.

7. Many of the cases of blindness and leucoma attributed to eye complaints during infancy, are perhaps due to xerophthalmia. Of late it has been said that blindness amongst children in Denmark is increasing while gonorrhoeal ophthalmia in new born infants at the maternity hospital is decreasing. Ophthalmo-blenorrhoea has been the cause of blindness in very few of the recent admissions to the blind institute, all of which supports my contention that xerophthalmia is the actual cause of the large number of blind children in Denmark.

The provision of an epidemiologically safe water supply to the Egyptian Expeditionary Force, as it fought its way across the Sinai Desert to deliver Palestine from the hand of the Turk, will long be remembered as one of the most remarkable achievements of the war.

In a recent number of this Journal1, I have pointed out that the well-known antagonistic action of Ca to Na, was probably at the bottom of the peculiar “defense rupture” action of Ca, as described by Bullock and Cramer2, in relation to infection with the organisms of gas gangrene.

The skins of grains, all flours and all bread contain bacteria belonging to the group B. mesentericus. The cultural characters of six types of B. mesenteriucus isolated from grains and flour are given. Five of these were also obtained from ropy (or sour) bread. None of these five types can be identified as corresponding to the organisms isolated by earlier workers on rope. Rope, or sourness, does not result from the presence of these bacteria unless conditions are such as to allow of great development. The factors determining development of rope in bread are (1) degree of infection, (2) moisture, (3) temperature, ? (4) reaction, and (5) composition of the flour. A method of estimating the degree of infection of flours is given.

This paper presents the results of a preliminary study of conditions affecting the movement of leucocytes. It demonstrates experimental facts which confirm the assumptions that osmotic force present in aqueous solutions and the permeability of leucocytes for water are the factors responsible for the movement of these cells from place to place.

Under the title of “The inference of local degeneracy from a comparison of the vital tatistics of the people,” the late Dr C. S. Morrison, Medical Superin tendent of the County and City Asylum, Hereford, published a somewhat alarming account of the local conditions (Journal of Mental Science, vol. LIII, 1907, p. 795). After showing that the mean quinquennial rate of admissions to the Asylum had risen from 4·8 per 10,000 inhabitants in 1871–1875 to 7·0 in 1891–1895 and after a slight drop in the succeeding period to 7·2 in 1901–1905. (not including boarded-out patients in the latter case), he proceeds to remark upon the prevalence of thyroid insufficiency.

THE following experiments form part of the general scheme of research undertaken with the object of providing a sound scientific basis for methods of fish preservation and storage.

The bacteriological part of the investigation was first undertaken by the author a year ago and the time has been spent in endeavouring to become acquainted with the peculiarities and characteristics of herring bacteria. There is still a large amount of work to be done in this field before practical experiments on a large scale can be carried out to yield really satisfactory results.