312 



quinine, which does not shew itself as haemoglo- 

 binuria. 



Microscopical investigations in this disease ■ 

 are frequently negative as regards malaria para- 

 sites, but it is all important when the examina- 

 tion is made, as the following analysis of over one 

 hundred cases microscopically examined shows : — 

 Parasites are present the day before the attack 

 in ninety-five per cent, of cases. 



Parasites are present the day of the attack in 

 seventy per cent, of cases. 



Parasites are present the day after the attack 

 in twenty per cent, of cases. 



In a series of cases examined by ourselves in 

 British Central Africa we found malaria parasites 

 only in i2"5 per centi, but, as we have already 

 shown, we have two further tests for a malarial 

 infection : — 



(i) The increase ini 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 psr cent., not i2'5 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. 



For the details of the proof we must refer to 

 the original papers, where also the causative action 

 of quinine is discussed. That quinine is the factor 

 which, in the large majority of cases, determines 

 the onset of haemoglobinuria appears to us equally 

 certain. 



