NTTTRIKNT MEDIA. 19 



inoculatod. At the end of twenty-four hours the stabs were distine'ily 

 visihh^, througliout their entire lcnt,'th in all the inoculated tubes (PI. 

 IV, fi<^. 1, A). In forty-eig-ht hours from the time of inoculation the 

 f^clatin in all the tubes bei;an to liquefy (PI. IV, tio-. 1, P), Li(|uefac- 

 tion advanced most rapidly in No. 3 and least rapidly in No. 1. In 

 three days No. o had entindy li(|uelied, and in live da^'s No. 1 and No. 

 2 had also liquelied (PI. IW iU^. 1, C). After the gelatin had li(iuetied 

 a cloud}' mass floated about in th(> clear liquid. This finally settled, 

 forming a copious white deposit. The deposit was most abundant in 

 No. 3, but in No. 1 it formed a layer from 2 to 5 nun. deep. 



J^f/f/ alhuiiwn. — Several tubes of soliditied eg-o- albumen were inocu- 

 lated Avith a fresh culture of the organism, but oidy a feeble growth 

 appeared and no change had ])eeii produced in the color of the 

 albumen at the end of eight weeks. 



Jfill:. — Thitj medium was sterilized ])y heating for ten minutes at 

 100*-^ C. in a steam sterilizer on three successive da3s, the milk having 

 been previously placed in test tubes (10 c. c. in each tube), and the 

 tubes closed with cotton plugs. The milk was inoculated b}' placing 

 a 1-nmi. loop of a 2-l:-houi'-old beef-))roth culture in cnch of several of 

 the tubes. The curdling of the milk began to take place in from two 

 to three daj^s in all parts of the inoculated tubes. Two days later the 

 entire 10 c. c. of milk was soliditied and a lajer of whey al)out 1 nnn. 

 deep rested upon the top of the curd. These experiments were 

 repeated from time to time, with the same results. Whey continued 

 to be separated for several days until from one-third to one-half the 

 space formerly occupied b}' the milk was occupied b}' the liquid; but 

 no abnormal coloring was produced in any of the tubes. None of the 

 control tubes curdled in any case. 



Litmus milJh. — This medium was prepared in the same manner as 

 the milk, except that a few drops of strong litmus solution were added 

 to each tube of milk before sterilizing. Several of the tubes were 

 inoculated with a 1-mm. loop of a 2i-hour-old beef -broth culture. 

 Within fort^-eight hours the blue began to give waj'^ to a reddish color 

 near the surface, which within three davs had extended throughout 

 the inoculated tube. At the end of five daj's from the time of inocu- 

 lation the red color had decidedlv faded throughout, so that the tubes 

 that were litmus blue when inoculated were now only faintly pink, and 

 the milk had curdled throughout. The curdling of the milk and the 

 separation of the whe}' took place in the same manner as if the litnms 

 had not been present. In nine days even the pink color had dis- 

 appeared, with the exception of a faint rim near the surface. These 

 discolored litmus tubes were then allowed to stand until the organism 

 had died. The red litnms color, eventually becoming blue, gradually 

 returned, although the milk remained curdled and the whey separated — 

 about one-half whey and one-half curd. 



