DIAGNOSIS OF MALARIA 523 



considerable blood destruction, often accompanied by 

 haemoglobinuria, and cachexia ; coma is another complica- 

 tion in certain instances, probably caused by massing of 

 the parasites in the cerebral capillaries. 



The cure of malaria by quinine is regarded as being due 

 to a poisonous action on the parasites analogous to that 

 exerted on numerous protozoa, amoebae, for example, 

 being injuriously affected by so little as a 1-50,000 solution 

 of quinine hydrochlorate. 



No toxin can usually be demonstrated in the blood of 

 those suffering from a malarial attack, but Rosenau and 

 his co-workers have found that the filtered blood, taken 

 when the temperature is rising, produces a malaria-like 

 paroxysm. By withdrawing blood containing parasites, 

 adding glucose, and incubating at 37 C., the multiplicative 

 cycle of the malaria parasite, as seen in the blood, is passed 

 through in the culture tube. 



A malaria-like parasite (Plas. Kochii) occurs in apes, in which it 

 produces fever. 



The nature of Blackwater fever, so called from the presence of 

 haematuria and haemoglobinuria, has given rise to much discussion. 

 By some it is considered to be a disease sui generis, of unknown 

 etiology. By others it is regarded as a form of malaria, either of 

 an intense type, or in which the kidneys are especially involved, or 

 as due to malarial infection plus quinine. It may be that under 

 particular conditions, of the nature of which we are at present 

 ignorant, haemolysins may be set free and cause haemolysis, the blood- 

 pigment being eliminated by the kidneys. 



Clinical Examination 



The blood of malarial patients may be examined either in the 

 unstained or stained condition. 



Examination in the unstained condition. The finger or lobe of 

 the ear is pricked, and a droplet of blood taken up on a clean cover- 

 glass, which is then placed upon a slide, so that the droplet of 

 blood spreads out into a thin layer between the two glasses. The 

 cover-glass may then be ringed with oil or vaseline to prevent 



