The Sterilization of American Foulbrood Combs 15 



of between 1 centimeter and 2 centimeters, 1 of these being attained 

 after 5 minutes, 1 after 15, and 1 not until 60 minutes had elapsed; 

 there were 3 cases of a rise of between 2 centimeters and 3 centi- 

 meters, 2 of them after 5 minutes, and 1 after 15 minutes had elapsed ; 

 in 1 case the liquid rose to the 3-centimeter mark in 3 minutes. 

 When no liquid passed through within the test period, ropy, diseased 

 material was found smeared on the inside of the capping, or the cap- 

 ping appeared unusually thick. As was to be expected, the alcohol 

 solutions passed through more readily in most cases than did water 

 solutions. One capping, not recorded in the table, was submerged in 

 water-formalin solution for three days with no perceptible passage 

 of liquid into the tube. 



Table 5. — Tests of the permeability of brood capping* to disinfectants 1 



Description of cappings 



Immersion 



Rise in tub* 



Fresh commercial alcohol -formalin solution: 



Dark brown from diseased comb, medium thick . 



Minutes 

 5 

 5 

 3 

 5 

 2 

 5 

 5 

 5 

 5 

 5 



5 

 5 



5 

 5 

 5 

 3 

 5 

 5 

 5 

 5 



5 

 10 

 15 



5 



10 

 15 



5 

 10 

 10 

 10 



10 

 5 



10 

 5 



60 

 3 



60 



10 

 5 

 5 



Centimeters 

 2.2 



Dark brown from diseased comb, - fairly thick... 



.9 



Dark brown from diseased comb, quite thin 



3.0 



Dark brown from diseased comb, thick 



.2 



Dark brown from diseased comb, slightly cracked 



3.0 



Dark brown from diseased comb, thick .. . 







Dark brown from diseased comb, medium 



1.1 



Dark brown from diseased comb, thick.. - 



Dark brown from diseased comb, thin ... 







2.8 



Dark brown from diseased comb, thick ... 







Used commercial alcohol-formalin solution: 



2.1 



Dark brown, old, from diseased comb, dried, thick . . 



.g 



Brown, old, from diseased comb, medium thin 



1.2 



Scale smeared over inside, thick .. .. 



.1 



Dark brown from diseased comb, thick ... 







Dark brown from diseased comb, thin .. 



3.0 





'0 



Dark brown from diseased comb, dry, medium thick. 



2.8 



Light brown from diseased comb, good condition .. 



1.0 



Dark brown from diseased comb, thick .. ... ... 



.2 



Fresh water-formalin solution: 



Dark brown from diseased comb, dried, thick . 



0.9 



Dark brown from diseased comb, thick . 







Dark brown from diseased comb, thin . .. 



1.7 



Dark brown from diseased comb, normal 







Dark brown from diseased comb, dried, thin . 







Do. 



2.4 



Dark brown from diseased comb, slightly cracked 



2.8 



Dark brown from diseased comb, thick.. . .._ 







Do 







Do 







Used water-formalin solution: 



Dark brown from diseased comb, dried, thick ... 



0.4 



Dark brown from diseased comb, dried, cracked . 



1.5 



Dark brown from diseased comb, thin 







Dark brown from diseased comb, very thin. _ . ... 



2.1 



Dark brown from diseased comb, thin 



1.1 



Dark brown from diseased comb, small hole 



3.0 



Dark brown from diseased comb, dried, thin ... 







Dark brown from diseased comb, thin 







Do.... 



.7 



Dark brown from diseased comb, cracked 



.8 







Tests made at a uniform depth of 3 centimeters below surface of solution. 



'Trace. 



To observe what actually takes place in a sealed cell when sub- 

 merged in a disinfectant solution, some artificial cells were made 

 with pieces of glass tubing of the same diameter as those used in the 

 experiment just described. Pieces of tube about three-quarters of 

 an inch long were sealed at one end and sterilized in a hot-air steril- 

 izer, cotton plugs closing the open ends. Scales containing virulent 

 spores of Bacillus larvae removed from diseased combs were then 



