Until recently there has been a general impression among a large proportion of the local medical faculty in Jerusalem that enteric fever was very uncommon and that typhus fever was practically unknown. As we are now basing our diagnosis of malaria increasingly upon the discovery of malarial parasites in the blood, we find that while on the one hand many of the most severe malarial infections, especially those with subtertian parasites, have little or no pyrexia, on the other hand, many cases which we should have called “ remittent malaria” or “malignant malaria” or “typho-malaria” in years gone by, are proving to be of other origin. A case of remittent pyrexia which does not yield in three, or at the outside five, days to efficient dosing with quinine is not in our experience a pure malarial infection.

1. Pigeons fed on daily rations of polished rice equal to 1/20th their initial body-weight develop symptoms of polyneuritis in about three weeks and usually lose considerably in weight.

2. The efficacies of various ox-tissues for preventing polyneuritis have been determined, and the tissues arranged according to their anti-neuritic powers are in the following descending order: liver, cardiac-muscle, cerebrum, cerebellum, voluntary muscle, and (cows') milk.

3. Alcoholic extracts of the excreta of a hen fed on unpolished grain and of the faeces of a rabbit fed on bread and cabbage cured polyneuritis in pigeons. The whole content of anti-neuritic substances present in the dietary was therefore not absorbed or else some amount is synthesised by the bacteria of which the faeces consisted to a considerable extent. No conclusions can consequently be drawn as to the actual distribution of the active substances in the animal body, until the extent to which the various tissues are absorbed from the alimentary canal of birds has been determined.

4. Nuts (husked filberts) are very efficient in preventing polyneuritis, being even superior to lentils and husked barley. Cheddar cheese, on the other hand, even in considerable amount, has no preventive effect.

5. Malt extract taken from two different samples readily cured polyneuritis in pigeons. A third sample however even in large doses had no curative action.

6. For the prevention of beri-beri egg-yolk, heart-muscle, liver, nuts, barley, and lentils can be recommended as suitable foodstuffs with which to supplement the polished rice diet. As meat (voluntary muscle) has been frequently found to be ineffective in preventing epidemics of beri-beri, its replacement by heart and liver in mixed diets would be a considerable improvement, because, not only are these tissues when suitably prepared as nutritious as voluntary muscle, but they also contain the anti-neuritic substances in much higher concentration.

It having been considered desirable that further experiments upon the range of flight of flies should be carried out, the investigation of the subject was entrusted to Dr E. Hindle and Mr G. Merriman, who are engaged in research in my laboratory. Although the experiments here recorded were carried out under somewhat adverse climatic conditions, they appear of sufficient interest to warrant publication, since the results with regard to the influence of wind seem to run counter to those recorded by previous workers, and also, apart from Hewitt's work referred to below, data have hitherto been wanting in respect of the range of flight of flies (Musca domestica Linn.) in towns. The simple graphic method of recording the results of the flight experiments, which occurred to me during the course of the work, may commend itself to others who may carry out similar investigations in the future.

Under the conditions of our experiments, indication was afforded that—

(1) House-flies tend to travel either against or across the wind. The actual direction followed may be determined either directly by the action of the wind, or indirectly owing to the flies being attracted by any odours it may convey from a source of food.

(2) It is likely that the chief conditions favouring the dispersal of flies are fine weather and a warm temperature. The nature of the locality is another considerable factor, as in towns flies do not travel as far as in open country, this being probably due to the food and shelter afforded by the houses.

(3) Under experimental conditions, the height at which the flies are liberated, and also the time of day, appear to influence the dispersal of the insects. As judged by one experiment, when flies are set free in the afternoon they do not scatter so well as when liberated in the morning.

(4) The maximum flight in thickly-housed localities in our experiments was about a quarter of a mile; but in one case a single fly was recovered at a distance of 770 yards. It should be noted, however, that part of this distance was across open fen-land.

In the course of our investigations on the biology of flies, during the year 1912, a certain number of experiments were performed in order to ascertain whether house-flies possess any colour preference. In the case of mosquitoes, Nuttall (1901) has shown that these insects have a very well-defined preference for certain colours. When a number of boxes, lined with different coloured materials, were placed in a tent containing mosquitoes, the latter occurred most frequently on navy-blue, and, in descending order, on dark red, brown, scarlet, black, slate-grey, dark green, violet, leaf-green, blue, pearl-grey, pale green, light blue, ochre, white, orange, and yellow. Very few insects indeed were found to rest on the last seven colours.

It is the custom in most laboratories where infected material is used during the progress of experimental work to have receptacles containing a disinfectant of some kind, placed so that the worker may drop any small piece of apparatus or culture into it which he has finished with, in order that such material should not be a source of danger to himself and to others in the laboratory. The disinfecting agent is more often than not some saponified tar-acid product, which, although lethal to naked bacteria may, or may not, destroy infection under the circumstances in which it is used. The fluid is also somewhat costly, apart from being uncertain in its action when resistant spores are being dealt with.

Experience gained from a previous enquiry on this subject in human tuberculosis led to the belief that much information might be derived from an investigation of the complement fixation reaction in animals experimentally infected with tubercle bacilli. Accurate dosage can be measured and the true path of infection is definitely known. Various enquiries were suggested and investigated by the detailed examination of rabbits and guinea-pigs; the latter class of rodents were used in batches of six to twelve in number, as otherwise the individual differences between animals in the same group of experiments are entirely overlooked. My cultures of the human tubercle bacillus were obtained by inoculating guinea-pigs with the sputum from typical cases of pulmonary tuberculosis at the Brompton Hospital Sanatorium at Frimley. Pure cultures of the bacillus were obtained from the infected guinea-pigs and cultivated on Dorset's egg medium, so that within a period varying from 14 to 21 days an abundant growth was obtained. The culture of the bovine bacillus was supplied to me by Professor Delépine who obtained it directly from the tissues of an infected cow, and subcultures were kept going on Dorset's egg medium. In every experiment without exception the animals were infected with definitely known quantities of the human or bovine bacillus. These were obtained by carefully scraping the growth off the surface of the egg medium and weighing it on sterile platinum foil, while in some cases (for comparison) a portion of the growth was dried in a desiccator before it was weighed. The untreated or dried bacilli were then shaken in a known quantity of sterile saline, so that a perfect emulsion free from clumps was obtained. The bacilli were kept in the dark in brown stoppered bottles and were always employed within a few days of their preparation.

In a previous paper (Lancet, 4·I·1913), we published a preliminary report on this subject and are now able to give further particulars of our results and to discuss in detail certain points arising from them.

The object of this portion of the investigation was to determine

(a) Whether the amount of immune-body present in the sera of cases of pulmonary tuberculosis, bore any constant relation to the stage of the disease and the condition of the patient.

(b) Whether well-marked clinical phenomena, e.g. periods of fever, attacks of pleurisy etc., were associated in any definite manner with variations in the amount of immune-body in the serum.

(c) Whether gradual definite and sustained improvement or deterioration in a patient's condition was accompanied by increase or decrease of the specific immune-body in the serum.

Early in 1912 Professor E. C. C. Baly, F.R.S., acting on behalf of Mr Jessup, brought one of us a collection of Swiss statistics and requested that it should be analysed, with the object of measuring the relation between the death-rates of cancer and diabetes. In the course of this work we have been led to consider many problems of theoretical and practical interest, bearing partly on the method of analysis and partly on the results yielded; it would not be possible to deal with all these in a single paper and the present memoir is devoted to a study of the problem first suggested, viz. the relation between the cancer and diabetes death-rates. Since, however, this may be the first paper of a series, it will be convenient to deal at some length with the nature of the investigation and the motives which led us to undertake it.

In works on Public Health and Water Analysis, it is a common observation that the amount of chlorine in inland surface waters near the seaboard is considerably higher than what obtains in samples from more inland parts.