2 44 
In a series of cases examined by ourselves in 
Nyassaland we found malaria parasites only in 12*5 per 
cent., but, as we have already shewn, we have two 
further tests for a malarial infection :— 
(1) The increase in the percentage of large 
mononuclear leucocytes. 
(2) The presence of pigmented large mono¬ 
nuclear leucocytes. 
By using these tests we were able to prove that 93*7 
per cent., not 12*5 per cent., of our cases were due to 
a malarial infection. 
Further, in the only case of blackwater fever seen 
by us before the onset of haemoglobinuria, 'parasites 
were present in abundance ; afterwards they rapidly 
disappeared. 
Examination of the Urine in Blackwater 
Fever 
1. Before the attack (if possible) examine for 
albumen, urobilin, reducing bodies, etc. 
2. Examine so-called ‘ high-coloured 5 urines. 
As a rule these do not shew bile pigment. 
3. Examine urine during an attack for methae- 
moglobin (or haematin), oxyhaemoglobin, urobilin, 
bile pigment (unusual), bilirubin crystals, haemoglobin 
casts, granular or hyaline casts, blood cells (rare). 
4. Centrifugalize the urine. Examine the clear 
layer (as in 3), and make films of the sediment. 
The sediment may contain hyaline and granular 
casts stained with haemoglobin. The mass of the 
sediment, however, consists of masses of haemoglobin 
of a yellowish-red colour. 
