6 
which were kept in the laboratory (20^ to 27° C.). cool chamber (17° to 
19° C.), and the dark room (20° to 23° C.), ^th the following results : 
Pieces of pine wood inoculated icith ioiiillon culture of bacillus pestis. 
Time. 
Labora- 
tory. 
Cool Dark 
chamber, room. 
Time. 
Labora- 
tory. 
Cool 
chamber. 
Dark 
room. 
4 da vs 
13 davs 


8 da vs 
— 
— 
18 davs 
— 
— 
— 
11 davs 
— 

21 davs 
The same culture was used to impregnate the pieces of pine wood as 
was used for the squares of crash in the preceding table, and these two 
objects thus infected were exposed to precisely the same conditions. It 
may therefore be assumed that the organism lives a shorter time on the 
one than on the other, 
PAPER IXEECTED WITH PLAGUE CULTURE. 
Another series of tests was made with pieces of filter paper and pieces 
of glazed (sized) paper. This paper is cut into little squares and steril- 
ized and impregnated in the usual way with a three-day-old bouillon cul- 
ture of the organism. These pieces were placed in Petri dishes and 
kept in the desk in my office where the temperature ranges from 20° to 
27° C. The results follow : 
Plague culture dried on paper. 
Time. 
Filter 
paper. 
Glazed 
paper. 
Time. Filter 
paper. 
Glazed 
paper. 
4 davs 
13 davs — 
8 davs 
— 
— 
18 davs — 
— 
11 davs 
— 
On account of the importance of this subject, a summary of the litera- 
ture follows : 
Kitasato (cl) found the organism alive after four days when dried on 
a glass cover slip and kept at 28° to 30° C. It grew after one to thirty- 
six hours, but not after four days. He used the pus of buboes from 
man. His experiments with serum cultures gave similar results. He 
was the first to study this question. 
W lEH (&) found the organism alive after four and one-half days on a 
glass slip. He exposed pure cultures at a temperature of 29° to fil° C. 
He could obtain no growth in bouillon after an exposure of four and 
one-half days. In vacuo, the bacilli were killed after an exposure of 
three hours. 
a Preliminary notice of the bacillus- of bubonic plague, Hongkong, July 7, 1894. 
b Uber die Pest epidemic in Hongkong im Jabre 1896. Hygienische Rundschau. 1897, 
Bd. VII, page 290. 
