EUROPEAN FOULBROOD. 33 



16. 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. 



17. The thermal death point of Bacillus pluton suspended in water 



is approximately 63° C. maintained for 10 minutes. 



18. Wlien suspended in honey DaciUus pluton is destroyed in 10 



minutes at approximately 79° C. 



19. Drying at room or incubator temperature Bacillus pluton re- 



mains alive and virulent for approximately one year. 



20. Wlien dry, Bacillus pluton resisted the direct rays of the sun for 



from 21 to 31 hours. 



21. "W^ien suspended in water Bacillus pluton was destroyed by the 



direct rays of the sun in from 5 to 6 hours. 



22. When suspended in honey and exposed to the direct rays of the 



sun Bacillus pluton was destroyed in from 3 to 4 hours. 



23. 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. 



24. In a fermenting honey solution outdoors Bacillus pluton was 



still alive and virulent after one month. 



25. 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. 



26. In a putrefying medium at outdoor temperature Bacillus pluton 



remained alive and virulent for more than 40 daj^^s. The maxi- 

 mum period has not been determined. 



27. In honey at room temperature Ba^TLus pluton ceased to be viru- 



lent in from 3 to 7 months. 



28. 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. 



29. 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. 



30. Experimental evidence indicates that at the present time drugs 



should not be depended upon in the treatment of European 

 foulbrood. 



