I have already warned the reader several times to avoid as much as possible sleeping in the houses of natives or in native villages. In such places native children are almost sure to be present; and as about half of these are likely to contain parasites, a large number of the old mosquitoes living about in dark corners are sure to be infected. In fact, many observers have actually found parasites in a large percentage (up to 25 per cent. or even more) of the Anopheles in native houses. A night spent by a European in such without a mosquito net is almost sure to result in infection. Indeed, a man may be thus bitten during a single night by perhaps five or six infected mosquitoes, and may acquire a very severe or even fatal infection in consequence. I cannot impress this fact too strongly on the reader-especially if he be a young man just going to or arrived in the tropics. Verbum sapienti. of the worst cases are produced in this manner. in a native house often means death. Some Nor are hotels and travellers' rest-houses always much better. It often happens that the stranger is ushered into a room which was formerly occupied by a patient, and which may have been kept shut up ever since, full of hungry, infected mosquitoes, which leap upon their new victim the moment he enters. I myself was infected in this manner in a dâk bungalow in India, in 1897. But it often happens that a traveller is compelled to take these risks. What is he to do then? If he is forced to sleep in a hotel or rest-house, or in a house formerly inhabited by natives, he and his servants should go round the rooms carefully, killing every mosquito they can find. If the rooms can be properly closed, sulphur may be burned in them (sec tion X). If not, it is advisable to flap round the walls and ceiling with a long towel, to shake the curtains, and so on. At night the mosquito net must be used with jealous care, and, if mosquitoes are in evidence, quinine should be taken for some time. If mosquitoes are numerous in a hotel it is usually due to nothing else but the ignorance or laziness of the manager. He should be sent for and told so. One can generally be candid with a hotel-keeper! The traveller or sportsman should never camp quite close to a native village if he can help it; still less should he give up his tents to go and sleep in houses lent to him by the headman. All these remarks apply as much to the prevention of yellow fever and elephantiasis as to that of malarial fever. XV. DOMESTIC PRECAUTIONS: RIDDANCE OF MOSQUITOES A list of domestic precautions is given in section XI. It is the duty of the head of the house in the tropics to see that all the inmates use mosquito nets at night. He should also have punkahs slung in the sittingrooms at least; or, failing these, purchase one or more electric fans. He should make it his principal duty to see that no mosquitoes are breeding anywhere within his premises. This is an easy task. After having carefully read section X, he should make it a rule to go round the whole of his house once a week-say on Sunday morning-in order to look for mosquito larvae or stagnant water. He should search every nook and cranny of his garden, backyard, servants' quarters, latrines, kit chen, stables, and sitting and sleeping rooms. Every broken bottle, empty sardine tin, broken floor pot, etc., should be placed in the dust-bin or in a large box (with a lid), to be removed by the scavenger or, if there is none, to be buried or otherwise disposed of. Cisterns, tubs, gutters, wells, pits, drains, should be looked to. If they contain larvae, these should be destroyed by oil or by sweeping them out, or other means; and then steps should be taken to preserve such water as is really required for household purposes by mosquito-proof covers. In my experience (a large one) a weekly round of this kind serves to keep a house nearly free of mosquitoes, even if they are breeding in the neighbours' houses. It also does good by stimulating the servants to keep the whole place clean. For further details see section X. XVI. DOMESTIC PRECAUTIONS: WIRE GAUZE If mosquitoes continue to abound in the house in spite of these measures; if there are many breeding pools or much bush in the vicinity, which it is impossible to get rid of; then wire gauze screens should be applied to the windows. In many localities, in isolated houses situated in the middle of forests or by the side of extensive marshes, this measure will often be the appropriate one. I think that it should also be employed in houses placed near the locations of natives, and in barracks and hospitals-at least unless the local authorities are actively and successfully extirpating mosquitoes on a large scale. Wire gauze can be purchased from many manufacturers (see advertisements). Brass or copper gauze will last longest; but it has been found in Lagos that tinned iron gauze lasts a long time; and it is cheaper. It is impossible to give full details here regarding the mode of protecting the house by this means, because every house differs so much in regard to the fastening of its doors and windows; the reader must make the arrangements for himself. One important principle must be closely attended to-not a single aperture must be left unprotected; ventilators, and even drains, must be guarded. For doors, I think it will suffice, as a rule, to provide an automatic shutting arrangement. For English sash windows (i.e., windows which slide up and down) it will generally do merely to nail up the gauze outside. For French windows (i.e., hinged windows which open outwards) it will generally be necessary to make similar windows furnished with gauze instead of glass, opening inwards. In many instances, however, it will be possible merely to replace the glass with gauze. In the tropics this gauze is not at all unpleasant. I found in Lagos, contrary to my expectations, that it does not shut out the breeze. On the contrary, it allows every breath of air to pass through it, and at the same time excludes flies, wasps, beetles, and moths, as well as mosquitoes. In short I recommend all who can afford it to screen their houses with wire gauze—or at least certain rooms in the house. This thing is constantly done in the Southern States. Unfortunately, this measure is likely to be adopted only by the owners of houses. The majority of Europeans in the tropics are merely monthly tenants of houses owned by rich natives and others. In such cases neither owner nor tenant is likely to go to the expense involved. It would pay local trading companies in tropical towns to undertake house-screening as a part of their business. The comfort of life would be largely enhanced by the measure at least if punkahs or electric fans are employed as well. XVII. DOMESTIC PRECAUTIONS: SEGREGATION, ETC. One of the chief reasons why Europeans are more healthy in India than in some other tropical countries, is, I think, because in India they generally live in separate quarters. In locations where the houses are surrounded by large gardens, infected mosquitoes are not likely to be so common as in houses surrounded by a poor and crowded native population. Unfortunately, where separate European quarters do not already exist it is as a rule impossible for individuals to segregate themselves without going out into tents. It is to be hoped, however, that the governments of our tropical colonies will exert their influence gradually to segregate the Europeans after the Indian fashion. In trading centres, much can be done by the owners of factories, etc., by buying out and removing the huts of natives from among the houses of the European employés. It is questionable, however, whether the money could not be generally better spent in keeping the whole surrounding area free of mosquitoes. Rank vegetation should always if possible be cleared away from the vicinity of houses, as it is very apt to harbour mosquitoes. Large trees are good at some dis |