MALARIA 283 



Wash one of the patient's finger-tips with soap and water, 

 and afterwards with ether, and dry carefully. Ligature the 

 end of the finger in the usual way, and prick the congested 

 pad with a fine clean needle. Wipe off the first drop of 

 blood which exudes, being careful to leave the skin quite 

 dry, so that subsequent drops shall not ' run.' Squeezing 

 the pricked finger-pad gently between finger and thumb, 

 express a second and smaller droplet of blood from the 

 puncture. This droplet ought not to exceed in size the 

 head of a large pin. Touch the apex of the droplet with 

 the centre of a cover-glass, and immediately lay this on a 

 slip. The blood will now run out between slip and cover- 

 glass in an exceedingly delicate film, in which, after a few 

 minutes, the red corpuscles will be found to be each of 

 them perfectly isolated, and lying flat on their sides. 

 Prepare several such slides. Reject all slides in which the 

 corpuscles in any considerable proportion are disposed in 

 rouleaux, or are heaped up upon each other. 



Perfect cleanliness of finger and slides, minuteness of the 

 droplet of blood, thinness of cover-glass, and a certain quick- 

 ness of manipulation, are the best guarantees for success in 

 obtaining the flat disposition of the blood corpuscles 

 absolutely indispensable. 



Examine the slides so prepared with a twelfth immersion 

 lens, and in not too bright an illumination. Scrutinise the 

 interior of every corpuscle in the field, looking in them for 

 specks of black pigment surrounded by a pale, hyaline, 

 slightly or markedly amoeboid substance ; also for smaller, 

 pale, unpigmented, hyaline, and more actively amoeboid 

 bodies in the same situation. These are the intra- 

 corpuscular and commoner forms of the malaria parasite, 

 and are always present in malarial fevers which have not 

 been treated by quinine. The crescent and flagellated 

 forms and the pigmented leucocyte — although the two 



