GOO MALARIAL FEVER 



individual's corpuscles by the malarial parasite, the occurrence of 

 lysaemia may be precipitated by an acute attack of malaria 

 especially when under certain circumstances this is associated 

 with the administration of quinine. On this view, however, it 

 still remains to be determined whether the lysis at the onset of 

 an attack of blackwater fever is due to a sudden liberation of 

 complement or to some other cause. 



Methods of Examination. The parasites may be studied by 

 examining the blood in the fresh condition, or by permanent 

 preparations. In the former case, a slide and cover-glass having 

 been thoroughly cleaned, a small drop of blood from the finger 

 or lobe of the ear is caught by the cover-glass, and allowed to 

 spread out between it and the slide. It ought to be of such a 

 size that only a thin layer is formed. A ring of vaseline is 

 placed round the edge of the cover-glass to prevent evaporation. 

 For satisfactory examination an immersion lens is to be preferred. 

 The amoeboid movements are visible at the ordinary room 

 temperature, though they are more active on a warm stage. 

 With an Abbe condenser a small aperture of the diaphragm 

 should be used. 



Permanent preparations are best made by means of dried 

 films, which films are fixed by one of the methods already given 

 (p. 94), or by placing in absolute alcohol for five minutes 

 (Manson). The films thus prepared and fixed may be stained 

 for two or three minutes in a saturated watery solution of 

 methylene blue or in carbol-thionin-blue (p. 105) ; the solutions 

 must be carefully filtered (especially the latter), and the films 

 must be washed well after staining. They are then dried and 

 mounted in balsam. In the case of thionin-blue, sharper results 

 are obtained by dehydrating in alcohol aud clearing in xylol 

 before mounting. The best results are, however, obtained by 

 one of the Romanowsky methods as described on p. 113. 



The fact that in many cases the parasites may be few in 

 number led Ross to devise a method for making their recognition 

 more easy by using blood films of unusual thickness. Here 

 about as much blood as is used in a haemoglobin determination 

 (20 c.mm.) is taken on a slide, and, being spread out only so 

 much as to occupy the area of an ordinary cover-glass, is allowed 

 to dry. There is then dropped on it by means of a glass rod a 

 little of the watery eosin used in making up the Romanowsky 

 dye (vide p. 113). This is allowed to act for about a quarter 

 of an hour, and then very gently washed off with distilled water, 

 The Romanowsky methylene-blue solution is then applied for a 

 few seconds and also carefully washed off, and the preparation 



