ADDENDUM 



.87 



5. Antiformin in the Examination of Milk for Tubercle 



Bacilli. 



In the text (p. 100) it is explained that it is advisable to 

 inoculate several guinea-pigs from each centrifugalised milk 

 sediment to determine if the tubercle bacillus is present, since a 

 certain proportion of the animals always die from the action of 

 other bacteria present in the milk. 



The chemical solution known as antiformin has been found 

 to readily destroy most bacteria, but the acid fast bacilli resist 

 destruction for a considerable time. This suggests the possibility 

 of treating the milk or the centrifugalised deposits before inocu- 

 lation with this substance so as to kill as many as possible of 

 the extraneous bacilli. 



The essential points which have to be settled before this 

 method can be employed are, on the one hand, the extent to 

 which the extraneous bacilli are killed or sufficiently reduced in 

 numbers, and, on the other hand, as to how far any tubercle 

 bacilli present are destroyed or their vitality injured by the 

 treatment with antiformin. The experimental results obtained 

 by Eastwood and Griffith 1 bear directly upon these points. 

 They found that neither 3 nor 5 per cent, solutions, with 

 exposures of 30 to 100 minutes, were sufficient to prevent over- 

 growth by extraneous organisms. Using a 10 per cent, solution 

 with times of action from 20 to 60 minutes the results were 

 variable, as in some cases pure cultures of the tubercle bacillus 

 were obtained, while in others this strength failed to eliminate 

 extraneous bacilli. 



1 5 per cent, and stronger solutions were found to be more or 

 less destructive to the tubercle bacilli, and in one experiment 

 even a 10 per cent, solution exerted some harmful action since 

 only scanty tubercle bacilli were recovered in pure culture. 



These experiments are in general agreement with those of 

 other workers with sputum, etc. While not conclusive they 

 suggest that treatment of milk sediments for 20 to 30 minutes 

 with a 10 per cent, solution of antiformin will very greatly 



1 Report of Medical Officer, Local Government Board, 1914, XLII, p. 203. 



