BACTERIA IN PNEUMONIA 155 



pig, under strong magnification, in hanging drop and dark 

 field illumination. 



7. The reaction is positive if in the fluid from No. i pig 

 the vibrios are dissolved, while in that from No. 2 and No. 3 

 the vibrios are very motile and active and form well pre- 

 served. 



It is necessary that the vibrio be of good virulence. 



Method of B or del. As experiment animals are not always 

 available, Bordet has elaborated a test-tube method. The 

 immune serum is diluted 1:50, 1:100, 1:500, and 1:1000. 

 Into a series of test-tubes there are poured 5 drops of a guinea- 

 pig serum, 5 drops of a mixture of suspected culture (one loop- 

 ful of an eighteen-hour-old agar culture to i c.c. salt solution), 

 and enough of immune serum and salt solution to make the 

 necessary dilution and up to 20 drops. A series of controls 

 is made with normal serum and the same amount of microbic 

 culture and guinea-pig serum. 



After eighteen hours the cholera vibrios will be active in the 

 control, but dissolved and clumped up in the tubes containing 

 the immune serum. 



CHAPTER XXII 

 BACTERIA IN PNEUMONIA 



KLEBS in 1875 called attention to the presence of bacteria in 

 pneumonia, and in 1882 Friedlander developed a bacillus from 

 the lung tissue of a pneumonic person which he thought was 

 a coccus, and called it pneumococcus. 



In 1886 A. Frankel and Weichselbaum proved that this 

 organism was not constant in fact, was rare. 



A. Frankel obtained in the majority of cases of pneumonia 

 an organism that he had described in 1884 under the name 

 of sputum-septicemia micrococcus. 



Weichselbaum called this Diplococcus pneumonia, and be- 



