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old tubs should be broken up, small puddles should be drained or filled up with stones and gravel; drains should be made good, gutters on the roof should be seen to, and so on.
The householder should go round his house and garden once a week and look into every place likely to harbour larvae. Of course the water must stand for at least a week before it will breed mosquitoes; and such water must be removed or treated with oil at the weekly visit.
In my experience, if all the stagnant water is re- moved from the premises, the adult mosquitoes inside the house which must have water to drink and lay their eggs in-soon fly away to the premises of more hospitable neighbours.
It is, in my opinion, possible to rid a whole town of mosquitoes by adopting concerted action against them. It is necessary to employ a sufficient gang of men con- stantly for the purpose of collecting old tins and bottles, etc.; draining and filling up pools and marshes; and training' the banks of streams and large bodies of water. In large towns in the tropics this should be done by the municipality; and I have been urging the measure on British Colonial Governments for some years. It is obvious that if in a town which contains, say, a thousand breeding places of mosquitoes, we reduce these to one or two, then we shall also re uce the total number of mosquitoes in the place by a large percentage. Of course a few insects may wander into the town from outside, and a few may continue to breed in collections of water, such as wells and large lakes, which we cannot get rid of; but these facts need not prevent us from putting a stop to the proliferation of the insects as much as we can within the area with which we are dealing.
As Dr. Harford-Battersby says in Climate To
