8

such a statement can be upheld for all we can say at present in regard to the dis-
tribution of the different varieties of malaria is that, as one approaches the tropics,
one finds infection with the malignant tertian form more and more frequent, a
statement which applies also to the frequency of Black-water Fever: and that
Blackwater Fever can arise from only one variety of the malarial parasite ,we
have at present no proof.

   It is then only with the intensity of malaria that we are concerned, and the
only portion of the objection that seems to merit consideration is the statement
that there are certain countries which are intensely malarious in which Black-
water Fever either does not occur or is very infrequent. Though it is repeatedly
averred that this is the case, the basis of fact for such a statement is extremely
slight.

   It has been stated that Black-water Fever is rare in Algeria; but the brothers
Sergent (39) have within recent years recorded 31 cases with 22 deaths, and Coste
(40) has reported another 25 cases, proving that the condition is far more
frequent than has previously been supposed.

   Black-water Fever is also stated not to occur in Egypt, a very malarious
country; but it is significant that it is common in parts of Palestine; and it is
being reported from the Soudan north of Fashoda.

   The greatest stress of all is laid on India. It has been stated that, whilst
people in India are much subjected to malaria and are accustomed to take
quinine freely, there is no Black-water Fever; and it is the same view which has
caused this country to be cited so frequently in the present connection.

   Manson (42) emphasizing the objection to the malarial origin of the disease
says, speaking of Black-water Fever: " It is exceedingly common among the few
Europeans who live in Tropical Africa, it is practically unknown amongst the
many thousands of Englishmen who live in the fever haunts of India."

   These views would no doubt be readily echoed by numbers of medical
men in India, who affirm, and we believe often quite rightly, that they have
never encountered the disease.

   At first sight therefore it might appear that there were grounds for the asser-
tion that in India while severe malaria is common Black-water Fever is gene-
rally speaking rare or absent, and should this view prove on enquiry to be
correct, it is obvious that it would form a serious objection. to the theory based
upon the suggested intimate relations between these diseases. Before giving
weight to this objection it is necessary to consider the history of Black-water
Fever in India and to note the circumstances in which it has appeared.