CHEMOTHERAPY 515 



sufficient quantities to impart demonstrable pneumococcidal prop- 

 erties to the serum when tested in vitro. 



In carrying out pneumococcidal experiments with derivatives of 

 cinchona, the technique, the temperature of the mixture, the dura- 

 tion of exposure, and the vigor and virulence of the organisms em- 

 ployed should be considered and should always be uniform. Solis- 

 Cohen and his colleagues advised for the best results a small 

 number of organisms and a long exposure to the action of the 

 drug. Kolmer and Idzumi, 743 in studying the effect of optochin on 

 Type II pneumococci in purulent spinal fluid, found that steriliza- 

 tion was complete in sixty to ninety minutes when the preparation 

 was used in a concentration of 1 to 10,000 but, in a concentration 

 of 1 to 50,000, optochin was ineffective. In a more highly purulent 

 empyema exudate containing Type I Pneumococcus, Kolmer and 

 Sands 749 noted death of the organisms after a thirty-minute ex- 

 posure at 37° to an equal volume of optochin in a 1 to 10,000 

 solution. Maeji 852 gave the following figures as representing the 

 effective pneumococcidal strengths of the cinchona derivatives 

 tested: optochin hydrochloride, 1:8,000 to 1:10,000; remijine, 

 1:8,000 to 1:10,000; quinine, 1:2,000 to 1:4,000; eucopine, 

 1:20,000 to 1:40,000; vuzine, 1:30,000 to 1:40,000. Mention of 

 the curative action of the compounds was not included in Maeji's 

 papers. 



A more delicate method for determining the bacteriostatic ac- 

 tion of optochin was that described by Schnabel. 1238 ' 1240 The re- 

 ducing property of the bacterial cell was chosen as an indicator of 

 the vital activities of Pneumococcus and the effect studied of the 

 drug on the ability of the organism to reduce methylene blue. 

 Schnabel reported that optochin in as low a concentration as one 

 to eight million was able to inhibit the reduction of the dye by the 

 strain of the Pneumococcus chosen for the test. The reaction could 

 also be utilized to determine the amount of optochin in the serum 

 of animals treated with the drug. 



