90 LOCAL TLSSUE REACTIVITY 



clays alier the last iiijcclioii or caiiicr il llic animals aj)|K'aic(l 

 sick. 



Hctcr()l()<>()iis sera Avere similarly prepared. B. lyj/ho.sii.s, B. 

 jjdxilyjjlio.sti.s A and B, and B. shlo^a sera employed in some e\- 

 j:)eriments, were prepared in the \e\\ ^'ork lioard ol Health Lab- 

 oratories by immnni/ation oi horses. ()ther animals employed in 

 this work 'were goats. 



As will l)e seen later from studies on the neutralizing anti- 

 bodies, goats and rabbits Avere imsuitable lor inninmization, 

 larger animals being more resistant to the toxic effects and yiekl- 

 ing more satisfactory results. Rabbit sera employed in this work 

 were selected from a large grouj) of animals receiving large doses 

 of the toxic filtrates and sin"\i\ing for a period of sexen xveeks. 

 Rabl)its injected repeatedly Avith large amounts of toxic fdtrates 

 survixed only rarely. Since at the stage of the work described here 

 nc^ large animals ^vere available, numerous rabbits used for repro- 

 duction of the phenomenon tci B. lyj/ho.siis in its \arious aspects 

 were saved and gixen repeated intraxenous injections. Only in 

 this manner I was able to obtain a few sera which proved espe- 

 cially potent. 



Tlie xvork described beloxv xvas carried out xvith fdtrates of 

 B. ty/jJiosus tryptic digest broth cidtures. The toxic filtrates were 

 mixed xvith sera in the desired proportions and the mixtiues were 

 incubated in the xvater bath at ^^7^ c. for cjne hour. Immediately 

 before injec:tion, the tubes xvere shaken. The fluid xvas injected 

 into various areas, usually the loxver right and upper and loxver 

 left areas of the epilated skin of the abdominal xvall. The upper 

 right area xvas injected xvith a toxic filtrate alone, previously 

 diluted xvith 0.9 per cent sodiimi chloride solution and kept in 

 the xvater bath at 37° c. for one hour, this site serving as a con- 

 trol of the susceptibility of the rabbit to the phenomenon. Some- 

 times the order of injections xvas changed. Txventy-four hours 

 later, the B. tyfjliosus culture fUtrate xvas injected intravenously 

 in a dose of 2 c.c. jjer kilo of body xveight. The readings xvere 

 made four to five hours after the intravenous injections. 



Since large intravenous doses of active principles xvere neces- 

 sary in order to ol)tain uniform reactions in all sites tested, some 

 of the rabl)its died earlier than four hours after the intravenous 

 injections and, therefore, no clear-cut readings of the results 

 could be made in these rabbits. The lethal effect of the prepara- 

 tion could not be reasonably predicted and changed from batch 



