CHAPTER X 



THE CELLULAR SUBSTANCE OF THE 

 PNEUMOCOCCUS * 



The Strain. The strain of the pneumococcus with which 

 this work was done was presented us by Dr. J. J. Kinyoun, 

 of Washington. When the culture was received, a mouse, 

 guinea-pig, and rabbit received intraperitoneal inoculations. 

 The mouse died in twenty-three hours, the guinea-pig in 

 twenty-four, and the rabbit in twenty-seven. Cultures 

 were made from the heart blood of each of these animals, 

 and all found to be pure. Our growths were made in 5 per 

 cent, glycerin bouillon, and with these, Roux flasks and 

 the tanks containing a medium made of 3 per cent, of agar 

 and 1 per cent, of ox serum in the 5 per cent, glycerin 

 bouillon were inoculated. The flasks and tanks were kept 

 at 38 for four days, when the growth was removed. The 

 growth seemed to reach maturity in this time at the tem- 

 perature mentioned. When kept longer it began to dry 

 and contract. In some instances the growth was not 

 harvested until the sixth day. The cellular substance thus 

 obtained was handled in the usual manner, i. e., it was 

 thoroughly extracted with alcohol and ether. 



The strain was found to be highly virulent and remained 

 so throughout the year of work with it. Fig. 10 shows the 

 effects of the living organism on guinea-pigs after intra- 

 abdominal inoculation of 0.00001, 0.000001, and 0.0000001 

 c.c. of a twenty-four-hour bouillon culture. 



Fig. 11 shows the relative effects of the living organ- 

 ism and 5 mg. of the cellular substance. It will be seen 



1 The first part of this chapter is founded on work done in the Hygienic 

 Laboratory of the University of Michigan in 1905-06 by Dr. J. F. Munson. 



