8 
hollows in the rocky soil, which are numerous in some sloping 
streets, are, during the wet season, violently scoured out almost 
every day — frequently more than once. The bearing of these 
facts will be seen later. 
It is, perhaps, worth while to add that the rainfall at 
Freetown is exceedingly heavy, even for the West Coast of 
Africa. The rains last from May until October, and the wettest 
months are July and August. The fall for August, 1899, was 
37*59 inches, and this was nearly 2 inches under the average for 
the last 13 years. 
At the western end of the town there is a marshy tract of 
grass-grown land known as " Grass-Fields," and most of the 
numerous creeks which run in from the sea close to and within a 
few miles of Freetown are bordered with mangrove swamps. 
In spite, however, of the belief (which may almost be dignified 
by the name of a creed) to the contrary universally entertained 
by residents, we found nothing to justify the idea that, at 
Freetown, at any rate, malarial fevers are due to the proximity 
of swamps. 
The Malaria Investigations. 
Before we had been two days at Freetown we received 
intelligence of an outbreak of fever among the patients (natives) 
in the lunatic asylum at the village of Kissy. The news was 
accompanied by specimens of a species of mosquito belonging to 
the genus Anopheles that had been obtained in the asylum by 
Dr. Berkeley, Assistant Colonial Surgeon, and Physician to the 
asylum. As Anopheles was the genus implicated in connection 
with human malaria by the previous researches of Ross and 
the Italian school (all experiments performed by the Italian 
investigators with Culex — the genus to which the majority of 
species of gnats or mosquitoes belong — having proved negative), 
the find was very interesting, and we lost no time in visiting the 
scene of the outbreak. It was found that the fever had occurred 
in one of the male wards. Of the three patients attacked, one 
hud died, another was still ill, and the third was convalescent. 
A titude<rf 4 WBaM species of Anopheles, most of the individuals being 
AnopheUi gorged with blood, was found resting on the walls in some 
IBID at rcht. 
