yo LOCAL TLSSUE REACTIVITY 



cultures ol B. l('jji.s('ljlicu.s, resuspended in NaCll solution in orig- 

 inal xolunic lacked phenomenon-producing potency, (lultmes 

 killed by heating and treated by the method oi Rowland em- 

 ployed for liberation of endotoxin were also inactive. Filtrates of 

 six day old cultures in Martin's bouillon heated 60° c. for one 

 horn- prior to filtration, gave the best results. 



It was also sho\vn by Joukow-Werejnikow and Lipatoxa that 

 the bacterial sediment derived from "agar washings" of B. jjc.sti.s 

 and washed several times in j^hysiological saline is totally de- 

 pri\'ed of the acti\'e j^rinciples. 



FLUCTUATIONS IN POTENCY OF ACTIVE PRINCIPLES 



The skin-preparatory and reacting factors fluctuate in potency 

 in the same filtrate. On several occasions there was observed a 

 gradual decrease in the j:otency as weW as complete inactivation 

 of the filtrates stored in the refrigerator for se\eral months, as 

 illustrated by the following example: 



One batch of meningococcus, 44B. Group IH, "agar washings" fihrates 

 was tested at frequent intervals for a period of four months. The jjotency 

 of the fihrate became somewhat lower four w^eeks after its preparation, re- 

 mained imchanged for three months thereafter, and ^vas suddenly lost alto- 

 gether four months after its preparation. 



It appears that the meningococcus culture filtrates are more 

 likely to lose their potency than the B. typhosus filtrates although 

 similar difficulties were occasionally experienced xvith the latter. 

 On the other hand, some filtrates may retain their potency un- 

 changed for a considerable length of time. A filtrate of B. dysoi- 

 teriae Shiga, retested more than fourteen months after its prepara- 

 tion, retained its original strength. 



Stolyhwo (1935) foimd that his filtrates of B. typliosus did not 

 deteriorate when exposed to light and to room temperature. He 

 evaporated the bacterial filtrates in a water bath. The dried mate- 

 rial, powdered and stored in sealed ampules, preserved its activity 

 for a period of six months. By suspending the powder in a quan- 

 tity of fluid smaller than the "mother" fluid, it xvas possible to 

 obtain a concentration of the active principles. 



Pabst and Branham (1933) also pointed out the possibility 

 that some preparations may remain stable fc:)r a number of months 

 whilst others may lose their potency rmexpectedly. They noted 

 an increase in activity during storage in the refrigerator. 



Cholera vibrio active principles of Lintc:»n, Singh and Seal 



