The Sterilization of American Foulbrood Combs 



13 



Table 4. — Cultural results of various tests with samples of comb treated for 2% 

 hours and for //S hours in various dilutions of alcohol- formal in and commer- 

 cial alcohol-formalin solutions 



Composition of solutions 



Commercial alcohol-formalin solution, 50 

 c. c, 20 per cent formalin in water, 50 c. c. 



Do -- 



Commercial alcohol-formalin solution, 40 

 c. c, 20 per cent formalin in water, 60 c. c~ 



Do 



Denatured alcohol (62.5 per cent), 80 c. c, 



formalin, 20 c. c --- 



Do 



Denatured alcohol (50 per cent), SO c. c, 



formalin, 20 c. c 



Do 



Denatured alcohol (40 per cent), 80 c. c, 



formalin, 20 c. c 



Do 



Denatured alcohol (50 per cent), 75 c. c, 



formalin, 20 c. c, glycerin, 5 c. c 



Do... 



Hrs. 



24 



48 



24 

 48 



24 

 48 



Q0 



3 a 





Open cells 



O bfi 



be |a 



Ms" 



■9«i|«8 



O ! g 



3 

 o 





Sealed cells 



OT 



o£ 



iSi- 





> a 



21 



— o 



O 



o . 









5n 



fto 



Si 



.Q 



3 



3 



g 











3 



3 



fc 



o 



o 



S3 



a2 

 oGb 

 "tog 

 8.9 § 



*.§? 



-^ v 



s u § 



« © a 



First. 

 Sixth. 



Third. 

 Seventh. 



Third. 

 Fourth. 



Third. 

 Fourth. 



Fourth. 

 Sixth. 



First. 

 Fourth. 



1 One showed few spores germinated. 2 Few spores germinated. 



COMMERCIAL ALCOHOL-FORMALIN SOLUTION 



Ten series of combs were treated with the commercial alcohol- 

 formalin solution at various times. From these combs 61 open 

 and 61 sealed sells were cultured. It was intended to use these series 

 as controls for comparison with other solutions, since published 

 reports of the success obtained with this commercial solution in 

 apiary practice indicated that negative cultural results would be 

 obtained. As may be seen in Table 7, however, in the case of 

 every one of the 10 preliminary 48 -hour series 1 or more sealed 

 cells, 22 in all, or 36 per cent, were found to give a growth of 

 Bacillus larvae. In 3 cases of the 22 the growths were noted as 

 " few spores germinated." No growth was obtained from the 61 

 open cells cultured. At first it was thought that the solution might 

 have deteriorated; fresh solution was obtained and tested, with 

 practically the same results. A chemical analysis of the actual 

 formaldehyde content of the fresh solution, and a similar analysis 

 of solution through which some 500 combs had been passed, showed 

 an actual increase with use in the percentage of formaldehyde. 

 This increase was without doubt due to the more rapid evaporation 

 of the alcohol than of the formaldehyde content. These results seem 

 to indicate that there must be a variation in the permeability of 

 cappings, the decrease in permeability slowing up or even pre- 

 venting the penetration of disinfectants to the scales and spores. 



