48 
BACILLUS TYPHOSUS. 
REVIEW OF THE AVORK OF OTHERS. 
Sternberg,® 1888, found that the temperature of 56° C. (138.8° F.) 
for ten minutes killed the Bacillus typJii abdominalis. Sternberg 
adopted ten minutes as the standaid time of exposure for his experi- 
mental work upon the thermal death point of a long list of micro- 
organisms. He took pains to insure uniform temperature by per- 
sonal attention and frequent stirring of the water bath with a glass 
rod. The micro-organisms were first drawn into hermetically sealed 
capillary tubes with expanded extremities. The tubes were im- 
mersed in a water bath, maintained at the desired temperature, for 
the standard time, namely, ten minutes. No attempt was made to 
fix the thermal death point witliin narrower limits than 2° C. 
Pfuhl,^ 1888, placed a number of test tubes containing a bouillon 
culture of typhoid bacilli with spores (?) in water baths at 50° and 
60° C. for ten, twenty, thirty, and fifty minutes. All the 50° cultures 
retained life and motility. In the 60° bath only those exposed ten 
minutes regularly showed movement and growth. 
Van Geuns,'' 1889, determined the effect upon bacteria of momen- 
tary heating to temperatures varying from 50° to 80° C. and imme- 
diate cooling. He used four methods : 
Method 1 : Stock-broth culture of the organism was introduced 
into 10 per cent gelatin tubes with a platinum loop. Some of these 
inoculated tubes were incubated as controls and the others placed in a 
water bath kept at a constant temperature. The control with ther- 
mometer in a gelatin tube showed that it took ninety seconds to reach 
80° C. and that it took about the same time to cool the tube in tap 
water to 12° C. After heating, the gelatin tubes were incubated at 
20°. This was the first method used by Van Geuns for a study of 
the common organisms in milk. 
For special purposes he adopted one of the following methods: 
Method 2 : Capillary pipettes were filled with broth cultures. The 
capillary tube was inserted into a cork along with a thermometer and 
both immersed into a test tube of water, which in turn rested in a 
water bath at Boiling temperature. As soon as the required tem- 
perature in the tube was reached it was removed from the bath and 
cooled. The capillary tube was then broken, and, with a needle,' 
stabs were made in gelatin. 
« Sternberg, Manual of Bacteriology, 1892, p. 146, and Report of the Committee on 
Disinfectants of the American Public Health Association. 1888, pp. 136 and 152 
(p. 140). 
b Pfuhl: Zur Sporenbildung der Typhusbacillen. Cent. f. Bakt., vol. 4, 1888, p.771. 
c Van Geuns: fiber das Pasteurisiren von Bakterien. Ein Beitrage zur Biologie der 
Microorganismen. Arch. f. Hyg., vol. 9, 1889, p. 369. 
