BLACK WATER FEVER 
209 
II. THE OCCURRENCE OF MALARIA PARASITES IN 
BLACK WATER FEVER 
Analysis of Ninety-five Cases 
PANSE has recently published a remarkable series of cases of blackwater, from 
which it is very evident that a positive or negative finding of parasites in 
blackwater depends very largely upon when the blood examination is made. 
This fact was already known to those who had made careful examinations in these 
cases, but I do not think that it is one that is at all generally recognized. I have> 
therefore, summarized all the cases, ninety-five in number, that I have been able to 
find bearing on this point. 
1 have confined myself to making clear this broad result, and have not con- 
sidered many other interesting features of the cases, e.g., (1) the data with regard to 
quinine, though quinine in itself is a powerful factor in causing the disappearance of 
parasites ; (2) the actual intervals in hours between a positive and a negative finding ; 
(3) the disappearance of parasites and their subsequent reappearance ; (4) the number 
of parasites at various intervals till they disappear ; (5) their occasional persistence 
throughout ; (6) the presence of pigmented leucocytes ; (7) the increase in the 
percentage of large mononuclear leucocytes (diagnostic of malaria). A consideration 
of such points as these would have much complicated the subject, and, indeed, the 
data are often quite inadequately given to make any such consideration possible, 
consequently I leave the tables to speak almost for themselves. 
I have not considered cases where a clear history exists of the taking of 
quinine for several days previous to the blackwater, because simple malarial cases 
under such conditions may give an entirely negative result. Nor have I considered 
cases, a few in number, where a relapse occurred a day, or a few days at most, after 
the initial attack, because these cannot rightly be considered as fresh cases. Such 
cases, for instance, as those of Koch's series, 13A, 13B ; in these the quinine element 
on the contrary is clearly demonstrated. Finally, for the above reason, I have not 
included a series of cases of Klein e, because, with one exception, the patient had been 
taking quinine for some days previously. The exceptional case was one where 
methylene blue had been given previously, and parasites were present ; quinine was 
then given, blackwater ensued, and the parasites quickly disappeared. 
The tables are constructed in the following way. The day before the black- 
water, the day of the blackwater, and the day following, form three headings, and 
under each of these is recorded the result of the microscopical examination as regards 
malaria parasites, whether positive or negative (without further detail), 
c 1 
