16. 
17. 
18. 
19, 
20. 
21. 
22. 
23. 
24. 
26. 
23 
28. 
29. 
30. 
EUROPEAN FOULBROOD. 33 
Experimental colonies may be inoculated and kept in the apiary 
without transmitting the disease to others. This fact is of 
special importance, not only in connection with the technique 
of making studies on the disease, but also in the control of the 
malady. 
The thermal death point of Bacillus pluton suspended in water 
is approximately 63° C. maintained for 10 minutes. 
When suspended in honey Bacillus pluton is destroyed in 10 
minutes at approximately 79° C. 
Drying at room or incubator temperature Bacillus pluton re- 
mains alive and virulent for approximately one year. 
When dry, Bacillus pluton resisted the direct rays of the sun for 
from 21 to 31 hours. 
When suspended in water Bacillus pluton was destroyed by the 
direct rays of the sun in from 5 to 6 hours. 
When suspended in honey and exposed to the direct rays of the 
sun Bacillus pluton was destroyed in from 3 to 4 hours. 
In the presence of fermentative processes in a 10 per cent sugar 
solution Bacillus pluton was destroyed in from 3 to 5 days at 
incubator temperature and in from 11 to 21 days at room 
temperature. 
In a fermenting honey solution outdoors Bacillus pluton was 
still alive and virulent after one month. 
. In the presence of putrefactive processes at incubator tempera- 
ture Bacillus pluton was destroyed in from 7 to 13 days and at 
room temperature in from 21 to 35 days. 
In a putrefying medium at outdoor temperature Bacillus pluton 
remained alive and virulent for more than 40 days. The maxi- 
mum period has not been determined. 
In honey at room temperature Bacillus pluton ceased to be viru- 
lent in from 3 to 7 months. 
Mixed with pollen, Bacillus pluton remained alive and virulent 
for more than 7 months at room temperature and more than 
10 months at refrigerator temperature, the maximum time not 
being determined. 
In one-half per cent carbolic acid solution Bacillus pluton was 
destroyed in from 8 to 18 days; in 1 per cent it was destroyed in 
from 5 hours to 4 days, and in 2 and 4 per cent in less than 
6 hours. The probability is that at these higher strengths of 
the solution minutes rather than hours are sufficient for the 
destruction of the virus. | 
Experimental evidence indicates that at the present time drugs 
should not be depended upon in the treatment of European 
foulbrood. 
