SEDGWICK AND WINSLOW. ^ BACILLUS OF TYPHOID FEVKn. 481 
below 3° C, although the growth on gelatine at the low t^uincraluiv was vcrv iiuhIi 
ded 
as vcrv 
Dr. Billings, in this countiy/^-^ described a .single experiment in whidi fivt: 
cubic centimeters of sterile water were inoculated witli the typhoid "-crm and frcxMn 
by the out-door cold. On the next day the frozen maf^s was tluiwod, and three gel.if inc 
tubes and one agar tube were inoculated with portions of it. Tlirce of flic four tubes 
showed typical growths. Chantemesse and Widal^*^' recorded the freezing of bouillon 
of the same microbe 
Bashcnow^^^ stated fhnt f\ 
germs survived exposure for thirteen days to a temperature between -8" and -](i C. 
Janowsky published in 1890 some very extended researches <®^ in which he used pure 
cultures of the typhoid bacillus in bouillon and froze them by means of ice and salt, 
ice and chloride of calcium or carbon dioxide and ether. He made no quantitntivc 
estimations ; but bouillon frozen by each of the above methods could still produce 
growth in Esmarch roll-tubes. Janowsky tried also the effect of successive freezings, 
using the calcium-chloride mixture. After the culture had solidified, it was left in 
the freezing mixture for fifteen minutes, then thawed in a water bath at 25°-30^ C, a 
sample taken, and the cycle repeated. This was done three times a day; and during 
the night the culture was kept at 2'— 5° C. After twelve such freezings sterilization 
had not been accomplished; the development of the frozen bacilli wa.«, however, much 
retarded. To imitate more closely the conditions in nature, Janowsky placed a 
bouillon culture and two flasks in which were threads bearing the germ in a dried 
condition, in a wire caare out of doors. Four sets of experlnientfl were conducted, in 
f which periods of seven, ten, and twelve days, respectively, did not suffice f( 
sterilization. In the fourth set of cultures the bo 
g 
after 
nineteen days; the minimum temperature during the period had been -17' C. and 
the -maximum 4"*, the culture thawing and freezing three times. Finally, among ex- 
periments on the typhoid bacillus must be mentioned a remarkable paper by Rem- 
linger,<«^) in which he states that he used a culture of B. typhi of such virulence 
that .5 c.c. would kill a guinea pig in 36-48 hours. He took agar cultures of this 
germ out of the incubator every two or three hours to immerse them in water, cooled 
down to 22-23°, for ten minutes. After ten days of this treatment the cultures had 
entirely lost their virulence, and after thirty-five days their power of growth as well. 
The author does not state whether control experiments were made or not. 
Even more extensive is the literature with respect to the effect of cold on the 
cholera vibrio. Koch, the discoverer of the or<^anism, stated that it was not destroyed 
temperature of -10° C 
Raptschewski*^' found that cholera germs 
dure for a month severe cold, rauirin^r «« low as -15° C, but that a temp 
31 
} 
