Perhaps our first and best defence against malaria lies in the habitual and scrupulous use of mosquito nets at night. Long before the connexion between malaria and mosquitoes became known, General Outram, Emin Pasha, and many others attributed their immunity from the disease to their care in this respect. Owing to the same precautions many students of malaria, including myself, have been able to work in the most dangerous places with impunity. I cannot say enough for the mosquito net. I believe that if all Europeans in the tropics could be induced to use it as carefully as some of us do, malarial infection would be reduced among them to less than a quarter.

In the cities and large stations of India, mosquito nets and punkahs are almost invariably used by Europeans; with the result that, though malaria abounds among the natives in these places, it is hardly known to attack Europeans. But in the planting districts of India and in Africa, nets and punkahs are not nearly in such general use; and it is just in these places that Europeans suffer so severely.

The first care of the resident in the tropics, of the traveller, the sportsman, the soldier, the miner, the clerk, should be for his mosquito net. Wherever he lives, wherever he goes, he should see that his mosquito net is with him, that it is in good order, and that it is properly arranged at bedtime. If the reader neglects this advice and of course I can only advise all that I can say is that he is pretty sure to suffer before long.

A person proceeding to the tropics should always take a net with him. If he lands without one, he may acquire a deadly infection the very first night he sleeps ashore.

Never allow yourself to be misled by statements

to the effect that there are no mosquitoes in such or such a locality. Read section VII, and put up your net religiously in spite of your 'friends.'

If your house is near a native location, or if you are a traveller and are forced to sleep in a hotel, or in the house of a native, or near a native village, redouble your precautions. It is just in such places that infected mosquitoes most abound.

But it is not enough merely to use a mosquito net-it must be used properly. The following rules should always be attended to:

Not a single rent or hole in the net should be allowed; if there is one, mosquitoes are sure to find it out and enter during the night.

The net should be so carefully tucked in under the mattress, or otherwise disposed, that no aperture is left under it.

The mesh should be not much larger than the head of a pin.

When in use the net should be stretched as tightly as possible in all directions, so as to permit every breath of air-so necessary to the comfort of the sleeper in the tropics-to blow through.

Have no entrance in the net; but, when, entering, lift the lower edge as little as possible and slip in with a twisting movement, so as to exclude stray mosquitoes which may have been hovering round you outside.

If possible, use a large bed and a large net in order to avoid the hands, feet, knees, and elbows being pushed against the gauze during your sleep, and being bitten through the net by mosquitoes outside. A mosquito house, placed round the bed, is good for this reason.

Instruct servants to hang the net before dark, and to see that there are no mosquitoes inside it. If mos

quitoes are found inside it in the morning it is due simply to carelessness.

If the bed is furnished with a square frame for the net, hang the latter inside the frame and tuck it under the mattress. Do not place it outside the frame and let it hang to the ground.

Some people say that they are stifled in a mosquito

This is only because they do not have the net properly stretched. Others say that all these precautions require too much trouble. They require no real trouble at all; in India, every sensible person is most careful in these respects. Why should not people be equally careful elsewhere?

The portable mosquito 'house' is very useful. People who can afford them should have two-one for sleeping in, and the other for reading and writing in (where punkahs cannot be used).

XIII. PERSONAL PRECAUTIONS: QUININE

As quinine destroys the parasites in the blood, it will prevent their multiplication in the system, even if they do obtain an entry by the mosquito's proboscis. It has been proved by experiments with numbers of soldiers and gaol prisoners that much less fever prevails among men to whom five grains of quinine are administered daily than among those who are not being treated in this manner. But five grains daily is not sufficient to prevent fever entirely; and it is doubtful whether even ten grains daily would suffice for this.

The objection to quinine is that it is apt to upset the digestion and to cause singing in the ears and even deafness. Considering the large degree of pro

tection which can be obtained simply from mosquito nets and punkahs, I do not, therefore, generally advise the habitual use of quinine in malarious places, unless perhaps the reader is one of those persons with whom quinine agrees well.

I do advise the reader, however, to take it as a preventive under the following circumstances:—

I. If he is forced to live in a house where there are, or lately have been, many cases of malaria; or in the house of a native; or in or very near a native village —even if he uses a net with all care.

2. If he is forced to do without a net; or if he has been much bitten by mosquitoes in spite of his net.

Many methods of taking quinine as a preventive have been suggested. I recommend five grains daily just before breakfast; with a dose of ten grains, instead of the five grains, twice a week. This should be continued for a month and then gradually reduced after leaving the exceptionally malarious place, a strong dose being taken occasionally. If the reader has been much bitten by Anopheles, I advise him to take ten grains daily for a fortnight, and then fall back on smaller doses. If large doses cannot be endured, it is, in my opinion, better to fall back on smaller ones, and to double other precautions, rather than to keep oneself in chronic ill-health in consequence of the drug.

nets.

For myself, I rely almost entirely upon mosquito

For some further details, see section XXV.

XIV. PERSONAL PRECAUTIONS: PUNKAHS AND OTHER MEASURES

The fact that Europeans enjoy so much better health in Indian towns than they have in Africa I attribute largely to the use of the punkah. Englishmen in India dress, eat, work, and sleep under punkahs -which not only drive off mosquitoes and other flies, but keep the body constantly cool and comfortable. This has the double effect of warding off malarial infection and of retaining the natural energy. In Africa, people sit, sweat, feed mosquitoes, and die.

I strongly advise residents in all tropical countries to follow the Indian example in this and other matters at any cost. People in India have learnt by centuries of experience how best to live in the tropics.

I also advise the directors of all business houses and factories to keep punkahs going over the heads of European employés during business hours—as is almost always done in India.

A punkah is a board, or framework covered with canvas, provided with a fringe, and hung by ropes from the ceiling. It is pulled by means of a rope which passes over a pulley and through a hole in the wall. The cost of having the punkah pulled for six hours daily amounts to about twelve pounds a year in Africa and about half that in India. The thing is worth the money.

Electric fans, worked by portable batteries, can now be purchased for ten pounds or so, and, as I have experienced, are a great comfort. They can be used. all night, and can be placed wherever required. When British enterprise awakes there will be a large demand for these in the tropics.