446 Proceedings of the Royal Physical Society. 
is correspondingly increased. In the absence of free renal 
secretion, copious diarrhcea may ensue, and may persist in 
spite of treatment till the wind abates. The other diseases 
are chiefly the result of the internal congestion set up by the 
cold, congestion going on to sub-acute inflammation of the 
liver and spleen, hemorrhages from mucous membranes, and 
abortion. Infants suffer severely from cold in the intervals 
between the harmattan. Slght attacks of fever unattended 
by prostration may occur; also rheumatic attacks, but these 
are arrested on the recurrence of the desert wind. 
According to Horton, the harmattan has a decided effect 
upon small-pox; the pustules soon heal up, and the disease 
disappears. Persons vaccinated whilst the harmattan wind 
is blowing are not protected against small-pox, as the vaccine 
will not take. 
I shall now deal generally with the incidence of malaria 
on the west coast of Africa. All I can do is to give a 
summary, which I hope may indicate with some attempt at 
accuracy, not only where the disease is prevalent, but where 
it is met with in its most grave forms. 
Some amount of confusion obtains as to the distribution of 
the graver forms of malarial fever in West Africa, This is 
due to the fact that some observers hold bilious remittent 
fever, blackwater fever, endemic hematuria, and typho- 
malarial fever to be distinct diseases. I do not agree with 
this view, and in what follows it must be distinctly understood 
that I entertain the conviction that these so-called various 
diseases are simply malarial fever distinguished by some 
prominent symptom which has given the name to a variety 
of that fever, as indicated above. Believing as I do that 
malaria is a disease swt generis, caused by the hzematozoon 
discovered by Laveran, I classify the results of its action on 
human beings as follows:—Intermittent feyer of varying 
types—‘ie., quotidian, tertian, quartan ague; remittent 
malarial fever, including bilious remittent fever, blackwater 
fever, hemoglobinuric fever, and endemic hematuria; per- 
nicious malarial fevers, including the comatose and algid 
varieties; masked malaria, including brow ague and the 
