MALARIA. 173 



the stain which we recommend for general use, and in 

 cases in which the nature of the organism (if one be 

 present) is entirely unknown. 



If bacteria are detected by any of these methods 

 their nature must be recognised by a consideration of 

 their morphological features and staining reactions. 



MALARIA. 



The blood in a suspected case of malaria may be 

 examined fresh or in stained films. Of these methods 

 the former is the better and should be used if possible ; 

 an examination of stained specimens should also be 

 made and is convenient, as it can be performed away 

 from the patient and at leisure. 



Fresh films are made by touching a drop of blood on 

 the patient's finger with the centre of a perfectly clean 

 cover-glass so as to remove an extremely small quantity 

 of blood. This cover-glass is then allowed to fall on to 

 a clean slide so that the droplet of blood may be spread 

 out by capillary attraction and by the weight of the 

 cover-glass, just as is the case in the method of making 

 blood films already described. But the slide is not 

 separated from the cover-glass ; they are examined just 

 as they are, a ring of vaseline being painted round the 

 edge of the cover-glass to prevent evaporation. 



The specimen is examined with a ^ in. objective, and 

 a place found in which the corpuscles are spread in a 

 single layer ; this part is then searched thoroughly with 

 a -% in. oil immersion lens. The parasites are seen as 

 pale irregularly-shaped bodies, with indistinct margins 

 which occupy the interior of the red corpuscles, and 



