MALARIA EXPEDITION TO THE GAMBIA 
35 
very small, and rain occurs only in four out of the twelve months of the year. 
Finally, in the dry season, as already stated, the breeding-places of mosquitoes occur 
only in the various yards and compounds. Excluding malaria, there are other 
reasons why an attempt at the destruction of mosquitoes should be undertaken in 
Bathurst, the close proximity of Dakar and St. Louis in the Senegal, at which places 
epidemics of yellow fever have broken out from time to time, is a danger to the 
inhabitants of Bathurst (in 1900, at Dakar and St. Louis, there were four hundred 
and ninety-five cases of yellow fever, with two hundred and twenty-five deaths), thus 
the probability of yellow fever being introduced into Bathurst from these ports by 
traders and others,* and its spread amongst the Europeans in this town by the means 
of mosquitoes is not to be disregarded. There is yet another disease very prevalent 
in Bathurst which is also spread by means of mosquitoes, namely, Filariasis. An 
examination of the blood of a number of the inhabitants revealed the presence of 
filarial embryos in thirty-four per cent, of those examined. Cases of Elephantiasis 
are frequently seen in the streets of the town. In Bathurst it is thus especially needful 
to diminish as far as possible the number of mosquitoes which infest the town. 
In chapter IV, I have described the various mosquito breeding-places occurring 
in Bathurst ; here it remains to discuss the methods most suitable for their abolition. 
Artificial Breeding-Places. The discarded domestic articles, including tins, 
bottles, calabashes, etc., must be collected and removed from all compounds in the 
first instance, and provision against their re-accumulation is necessary ; this might 
be accomplished by a systematic collection under the supervision of the Sanitary Board. 
The rain tanks and barrels for the storage of rain water require well-fitting covers ; 
such tanks should not be allowed in compounds without anti-mosquito covers, as 
not only do they breed mosquitoes, but the stored water soon becomes foul by dust, 
dirt, and insects which collect in them. Water tubs required for the soaking of fibres 
should be completely emptied at least once a week, and refilled with fresh water. As 
a further safeguard, kerosine oil should be applied to the surface of the water when 
the tub is refilled. Tubs for the storage of water for gardening purposes should be 
limited in number, and only sufficient water for the day ought to be stored in them. 
These tubs should be completely emptied of water by turning them upside down every 
day ; it this is not done a very considerable quantity of mosquito larvae are likely to 
remain in the small quantity of water left in the bottom of the tub. Gutters round the 
ground-nut stores, when filled with water, should be treated at the same time with 
kerosine oil, an ounce of which would probably be sufficient for each gutter. 
Boats. The following methods of dealing with boats naturally suggest them- 
selves : old boats and canoes should not be allowed to remain on the beach, such 
discarded boats should be broken up. Boats awaiting repairs should be turned bottom 
uppermost, larger boats and hulks, staying short periods on the beach, should be carefully 
See Chapter I 
