276 



The Phagocytic Power of the Blood 



Miller* says that " a good smear should be uniform in consistency 

 and most of the leukocytes should be found along the edges and 

 at the end. For convenience in counting, it is well to have the 

 smear terminate abruptly and not be drawn out into threads or 

 irregular forms." 



Fig. loi. — A small incubator of special design for opsonic work (Miller). 



This mixing, incubating, and spreading is done twice — once 

 with the serum of the patient, and once with the normal serum of 

 the operator. The technic is the same each time. In order that 



the enumeration of the bacteria 

 taken up by the leukocytes can 

 be accomplished, it is next neces- 

 sary to stain the blood smears. 

 This can be done by any method 

 that will demonstrate both the 

 bacteria and the cells. For 

 staphylococci and similar organ- 

 isms, Leishman's stain, Jenner's 

 stain, or J. H. Wright's stains are appropriate. Marino's stain, 

 recommended by Levaditi,t gives beautiful results. For the 

 tubercle bacillus the spreads may be stained with carbol-fuchsin 



* "Therapeutic Gazette," March 15, 1907. 



t "Ann. de I'lnst. Pasteur," 1904, xviii, p. 761. 



Fig. 102. — The smear (Miller). 



