EXPERIMENTS WITH FOBMALDEHYDE GAS. 39 



1. The greatest number of infecting germs are found in the bodies 

 of dead larvfe. 



2. The pollen stored in the cells of the foul-brood combs contains 

 many of these infecting organisms. 



3. The honey stored in brood combs infected with this disease has 

 been found to contain Bacillus alvei in small numbers. 



4. The surface of the combs, frames, and hives may be contami- 

 nated. 



5. The wings, legs, head, thorax, abdomen, and intestinal contents 

 of adult bees are found to be contaminated with Bacillus alvei. 



6. Cheshire (29), Mackenzie (30), and others have found Bacillus 

 alvei in the ovary of the queen. This has suggested a means of in- 

 fection. From a bacteriological examination of queens from three 

 badly infected hives we were able to isolate Bacillus alvei in small 

 numbers in two cases. Since a very large number of this species of 

 bacteria may be found in the intestinal tract and upon all parts of 

 the body, it is very probable that such findings are the results of con- 

 tamination in making cultures and have no special significance. 



Experiments with. Formaldehyde Gas. 



Within the last few years several articles have appeared in the bee 

 journals entertaining great hopes that a cure for foul brood has been 

 found in the use of formaldehyde gas. The methods described for its 

 use have been tested by the apiarists and bee experts in New York 

 State, with the result that the disease sometimes breaks out anew In 

 colonies so treated. 



In order to test the value of formaldehyde gas as a disinfectant 

 when used in foul-brood combs a number of experiments were made 

 in the laboratory. A common frame hive was first used, in which 

 were placed specimens of foul brood. The hive was charged with 

 gas by heating formalin in a closed vessel which was in communica- 

 tion with the hive; 15 c. c. was used each time and evaporated to 

 dryness. The charging of the hive with gas was repeated in this 

 way at the end of 2, 4, 6, and 20 hours. Before each charging and 

 at the end of 24 hours after the first application of gas, cultures were 

 made. Of all the tubes inoculated 90 per cent showed Bacillus alvei 

 to be present. There was no decrease in the number of tubes in 

 which Bacillus alvei appeared following the several applications of 

 formaldehyde gas. 



The examination of specimens of foul brood which had been treated 

 with the gas by an apiarist gave the following results : 



Thirty tubes which were inoculated from larvae, capped and un- 

 capped, showed the presence of Bacillus alvei in 21. 



Thirty tubes which were inoculated with pollen in cells gave 

 Bacillus alvei in 28. 



