SLEEPING SICKNESS 
83 
long time, perhaps for the rest of its life, for the trypano- 
somes which entered it in the blood it sucked live and 
increase and pass in its saliva into the blood of any one 
it bites. 
Still closer study of sleeping sickness revealed the fact 
that it can be also conveyed by mosquitoes, if these 
insects take their fill of blood from a healthy person 
immediately after they have bitten any one with sleeping 
sickness, as they will then have trypanosomes in their 
saliva. Thus the mosquito army continues by night 
the work which the glossina is carrying on all day. 
Poor Africa ! * 
In its essential nature sleeping sickness is a chronic 
inflammation of the meninges and the brain, one, how- 
ever, which always ends in death, and this ensues be- 
cause the trypanosomes pass from the blood into the 
cerebro-spinal fluid. To fight the disease successfully 
it is necessary to kill them before they have passed from 
the blood, since it is only in the blood that atoxyl,f one 
weapon that we at present possess, produces effects 
which can to any extent be relied on ; in the cerebro- 
spinal marrow the trypanosomes are comparatively safe 
from it. A doctor must, therefore, learn to recognise 
the disease in the early stage, when it first produces 
fever. If he can do that, there is a prospect of recovery. 
In a district, therefore, where sleeping sickness has to 
be treated, its diagnosis is a terribly complicated busi- 
ness because the significance of every attack of fever, of 
* I must, however, in justice add that the mosquito does not 
harbour the trypanosomes permanently, and that its saliva is 
poisonous only for a short time after it has been polluted by the 
blood of a sleeping sickness victim. 
I Atoxyl (meta-arsenic anilid) is a compound of arsenic with an 
aniline product. 
