70 Report OF THE BACTERIOLOGIST OF THB 
Small drops of this liquid were transferred to sterile cover 
slips placed in sterile Petri dishes. These drops dried up within 
a few minutes leaving a film of germs upon each cover slip. The 
Petri dishes each containing five cover slips, were then wrapped in 
paper and placed in a closed drawer at a temperature of about 
Me Be 212 GC.) 
Each day five coverslips were transferred each to a sterile Petri 
dish and melted agar added. At the end of several days transfers 
were made from the resulting colonies to sterile potato upon 
which P. campestris produces most characteristic growth. Pure 
cultures were also preserved for further identification. 
The results of three such tests may be summarized as follows: 
During the first two days a large part of the germs are destroyed 
and by the end of the third day few survive. From the third to 
the tenth day an occasional germ is found alive but we have not 
found one alive after ten days. In many cases they were all 
dead on a coverslip before the end of the third day. 
PLAN OF TEST ON CABBAGE SEED. 
In view of the above results it seemed hardly probable that the 
germs on the seed would survive long enough to be a source of 
danger. To settle this point it was decided to infect some seed 
heavily and observe the length of time that the germs would 
survive. . 
In the test of April 29, 1903, a vigorous growth of P. campestris 
two days old on agar slope was covered with ten cubic centi- 
meters of water and thoroughly stirred into the water. This 
emulsion was filtered through paper to remove the larger solid 
particles and 5 ce. of the filtrate poured over 260 cabbage seeds 
(var. Early Jersey Wakefield). After the seeds had soaked in 
the germ-impregnated water for a few minutes they were spread 
out to dry for about four hours. hey were then thoroughly 
dry. Five seeds were placed in each of 52 sterile test tubes 
plugged with cotton. Twenty-six tubes were left in this condi- 
tion while the other twenty-six were sealed by paraffining the 
cotton plugs. The whole 52 tubes were then put into covered 
pasteboard boxes and stored in a room which was kept at a tem- 
perature ranging from 60°-70° F. (16-21° ©.). The object of 
paraffining a portion of the tubes was to prevent excessive drying. 
By treating the seeds in these different ways it was hoped to 
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