276 The Philippine Journal of Science wis 



since by keeping stock cultures of cholera growing in bile 

 medium. 



The present investigation consists of three experiments, 

 namely, with glycerin, with sodium chloride solutions, and with 

 bile, respectively. Although these experiments have not been 

 carried out simultaneously, the salt solution used in each of the 

 experiments serves as tertium comparationis and allows fair 

 comparison of the results of the three groups of experiments. 



EXPERIMENT I. GLYCERIN 



About 3 grams of stools were ground up in 30 cubic centi- 

 meters of 0.6 per cent salt solution. The mixture was filtered 

 through cheesecloth. Twenty cubic centimeters of 0.6 per cent 

 salt solution were added to two 24-hour old cultures of cholera 

 vibrios, the cultures were washed, and the suspension was added 

 to the filtrate of the stool mentioned above. Thus prepared arti- 

 ficial cholera-stool emulsion was thoroughly shaken in a flask 

 containing glass beads. 



Five cubic centimeters of 0.6 per cent salt solution and 40 

 per cent, 50 per cent, and 60 per cent glycerin, respectively, 

 were put into four separate sterile test tubes, and to each one 

 of these were added 5 cubic centimeters of the above suspension 

 of faeces. The tubes were then thoroughly shaken and left at 

 room temperature (32° C). One peptone water culture was 

 planted from each of the four tubes immediately by transferring 

 three loopfuls of their content. After twenty-four hours' in- 

 cubation Dieudonne's plates were made from the peptone cul- 

 tures. At the end of twenty-four hours' incubation the colonies 

 that developed on the plates were examined. Smears were made, 

 and microscopic agglutination was performed. 



The three tubes containing the mixture of artificial cholera 

 fasces and glycerin in various strength of percentage as well as 

 the fourth tube containing no glycerin but only salt solution were 

 examined daily for the presence or the absence of cholera vibrios 

 by the procedure just described. 



The results of this experiment (Table I) show that glycerin 

 has no preserving action for cholera vibrios. In 20 per cent and 

 in 25 per cent concentrations the cholera vibrios survived four 

 days only, while in the tube containing 30 per cent glycerin no 

 cholera vibrios could be found on the fourth and the subsequent 

 days. These findings are in accord with those obtained by 

 Ruediger, who made similar observations while testing the ger- 

 micidal action of glycerin. 



