270 SPECIFIC MICRO-ORGANISMS 



down the leukocytes and fibrin. The supernatant fluid is then 

 transferred to a clean tube and whirled at high speed to sediment 

 the bacteria. The supernatant fluid is discarded and the bacter- 

 ial sediment is suspended in salt solution sufficient to make a 

 translucent mixture. Five tubes are then set up as follows : 



Tube I — 0.5 c.c. of I : 20 dilution Type I serum, 0.5 c.c. of 

 the bacterial suspension. 



Tube 2 — 0.5 c.c. of undiluted Type II serum, 0.5 c.c. of the 

 bacterial suspension. 



Tube 3 — 0.5 c.c. of I : 20 dilution Type II serum, 0.5 c.c. 

 of the bacterial suspension. 



Tube 4 — 0.5 c.c. of I : 5 dilution of Type III serum, 0.5 c.c. 

 of the bacterial suspension. 



Tube 5 — 0.1 c.c. sterile ox bile, 0.3 c.c. of the bacterial 

 suspension. 



The tubes are immersed in water bath at 37" C. for one hour. 

 Agglutination in the homologous type serum is usually prompt. 

 If no agglutination occurs after one hour and the organism is 

 a bile soluble encapsulated diplococcus, it is classed as a pneu- 

 mococcus of Group IV. If agglutination is present in Tube 2 

 but absent in Tube 3, the organism is classed in Subgroup II. 



Various simpler methods^ of typing pneumococci have been 

 devised, but they are less reHable even in expert hands. 



Kyes^ has injected chickens with, massive doses of pneumo- 

 cocci and has obtained a powerful anti-serum which seems to be 

 potent against various strains and types of pneumococci. Fur- 

 ther confirmation of his^results should be awaited. 



Streptococcus Viridans.- — Scbottmueller* has found a strepto- 

 coccus, resembling in some respects the pneumococcus, in the 

 blood of cases of subacute endocarditis or endocarditis lenta. 

 On the blood-agar plates the colonies appear after two to five 



- Mitchell and Muns; Journ. Med. Rsch., 1917, 37, p. 339. 

 Avery, O. T.; Journ. Amer. Med. Assn., 1918, 70, p. 17. 

 ^ Kyes, P. Journ. Amer. Med. Assn., 1911, 56, p. 1878; Journ. Med. Rsch., 

 1918, 38, p. 495. 



' Muenchener med. Wochenschr., 1903 (I), No. 20, p. 849. 



