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MALARIAL FEVERS.

The total number of deaths among the Chinese from the Malarial Fevers was 887, as compared with 532 during the previous year and 506 during 1898; this is equal to a death-rate of 3.3 per 1,000. The death-rate among the boat population alone from this cause was 2.2 per 1,000, less, that is to say, than among the land population, as in 1899.

The Colony has endeavoured to keep pace with the recent researches into the aetiology of Malaria, and in October last! submitted the following minute to the Sanitary Board and it was sub- sequently published for general information.

"The modern theory in regard to the transmission of Malaria is that the disease is conveyed from man to man by certain mosquitoes belonging to the genus Anopheles,' of the Dipterous (or two- winged) Family ‘Culicidæ.'

It has long been known that true Malaria is associated with the presence of certain minute orga- nisms in the blood of the patient and it can readily be understood that when a patient suffering from Malaria is bitten by a mosquito, some of these organisms are taken (with the blood) into the body of the mosquito. The malarial organisms there undergo certain developmental changes and should the same mosquito subsequently bite a healthy person, he becomes inoculated with the disease, and may develop an attack of Malaria.

The Anopheles differs from the ordinary mosquito (genus Culex') in that its approach is not heralded by that noisy 'ping' that characterizes the latter; that its bite is not nearly so irritating to the skin; that it rarely bites except between sunset and sunrise, and that while the 'Culex' will breed in any old flower-pot or tin containing water, the Anopheles is fortunately more choice in its selection of a breeding ground, and generally requires a small sheltered pool, containing perhaps organic matter in suspension or a small quantity of water weed, and the water of which is neither stagnant nor yet pure spring water. The Anopheles' can travel a distance of some 400-500 yards and can remain alive for a period of several months-that is to say, throughout the whole of the dry

season.

Asiatics, and especially children, suffer more or less constantly from Malaria, as they adopt no means of protection from the bites of mosquitoes, and 'Anopheles' are almost always to be found in the neighbourhood of native dwellings while some 1 to 5 per cent. of them will be found to contain the malarial organism. It follows therefore :-

(1.) That European houses should be distant some 400-500 yards at least from native dwellings.

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(2.) That all pools in which Anopheles' can breed should be filled up or drained, for a like distance, around such European houses.

(3.) That all brushwood and rauk vegetation, including grass, should be kept down by frequent cutting.

(4.) That mosquito-nets should be used at night."

A certain amount of work was done during the year in the direction of the treatment of some of the Anopheles pools with paraffin, and of the filling up of others with concrete, but apparently with- out any great success, if we may judge by the number of deaths from Malarial Fevers recorded, which greatly exceeds that of previous years, and I am afraid that nothing but a thorough scheme of training of the Nullahs on the outskirts of the City will have any appreciable effect in reducing the number of mosquitoes capable of carrying infection.

In a recent Report to the Royal Society, Drs. STEPHENS and CHRISTOPHERS, who are working at this subject in Lagos, say that "to stamp out native malaria is at present chimerical, and every effort should rather be turned to the protection of Europeans," and I certainly think that the same principle holds good in this Colony. The Colony has recently acquired a very extensive addition to its terri- tory and every effort should be inade to secure and maintain an extensive European reservation in this new territory, before the land becomes too valuable for the Government to be able to resume from the native holders. This reservation should be surrounded by a zone of neutral ground, at least a quarter of a mile wide, on which neither European nor native dwellings should be allowed, but which should be utilized by the Government for the cultivation of trees or laid out in part as a recrea- tion ground. There is no objection to a small number of personal servants residing within the reservation area, but in no case should any native families be allowed, as it is the native children, and especially those under the age of ten years, who are the principal source of infection in Malaria.

In view of the very considerable number of deaths from Malarial Fever among the Troops, it would appear to be especially important that all Barracks should be isolated in this manner from the native population.