BLACKWATER FEVER 109 



regards dose of quinine or interval between taking 

 quinine and the onset of haemoglobinuria, as might have 

 been anticipated if the quinine acted as the determining 

 cause. In a few instances quinine has not been taken. 

 In many the dose taken is no larger than, or not as large 

 as, the person was in the habit of taking, and after 

 the onset of haemoglobinuria further administration even 

 of large doses of quinine does not, usually, cause fresh 

 haemolysis. In cases in England the usual history is 

 that whilst in Africa regular prophylactic doses of 

 quinine were taken, in England the patients either dis- 

 continued the drug or took it irregularly, or only when 

 they felt seedy or had fever. Irregularity in the use of 

 quinine appears to be the important factor in many cases, 

 and blackwater fever is rare in those who take 5 gr. of a 

 salt of quinine quite regularly. By some the sulphate is 

 believed to be the salt which is most likely to pre- 

 cipitate or induce an attack of blackwater fever, as 

 sulphates cause a decrease in the organic salts in the blood 

 and may upset osmotic equilibrium. But attacks occur 

 in persons who only use the hydrochloride. Exposure 

 to cold and wet seems to often act as the determining 

 cause, but a few of the cases occur amongst persons who 

 have no chance of such exposure. 



Various hypotheses have been formulated in the 

 attempt to explain why a disease which appears to be 

 closely connected with malaria is not directly due to the 

 malarial parasite. A want of balance between the pro- 

 duction of haemolysins and antihaemolysins, dependent 

 partly on the parasites and partly on blood changes 

 in the host as a result of the formation of antibodies, 

 appears to be the most promising, or it may be con- 

 sidered as a phenomenon of anaphylaxis. 



Sequela?. In the majority of cases recovery is com- 

 plete, and there are no persistent ill-effects beyond a 

 liability to subsequent attacks. Sometimes a malarial 

 attack will occur, but as a rule there is freedom from 

 such attacks. In rare cases there may be persistent 



