98 Journal of Agricultural Research vol. xx, no. 2 



as NaOCl or HOG, in Dakin's solution and eusol, respectively, chloramin 

 T must be regarded as less efficient than Dakin's solution or eusol against 

 naked spores. In the presence of blood serum it is more or less equal 

 to Dakin's solution, while eusol seems to be superior to both chloramin 

 T and Dakin's solution. Comparison on the basis of "available" chlorin 

 would, of course, be much more favorable to chloramin, since it contains 

 only 25 per cent available chlorin, or 12^2 per cent actual chlorin. 



It is interesting to note that in experiments 16, 17, 18, and 2 1 chloramin 

 T was more efficient against anthrax spores in the presence of blood 

 serum than in the absence of serum. In experiments 16 and 17 this is 

 true only for the stronger dilutions (10 per cent and 5 per cent) and is 

 not true for the lowest dilution (1 per cent). In experiment 18 it is 

 true for 2 per cent and 1 per cent dilutions after 24 hours, but in experi- 

 ment 20 with dilutions of 1 to 100 and 1 to 200 and exposures of 2 days 

 there is greater efficiency without serum than with it. Experiment 21 

 confirms the results obtained in experiments 16 and 17 with a 5 per 

 cent dilution. 



These experiments also seem more or less at variance with the widely 

 expressed opinion that chlorin compounds rapidly lose their activity 

 and soon become inert, especially in the presence of organic matter. 

 For example, in experiment 20, HOC1 1 to 200 did not destroy anthrax 

 spores until after an exposure of 2 days, the 4-day result serving as a 

 control to show the correctness of the result. 



This usually accepted opinion is controverted by Rideal (9), who as 

 the result of his own experiments concludes that — 



chlorin has a disinfectant value out of all proportion to that which would be expected 

 from the hitherto accepted theories, even in the presence of a chemical excess of 

 organic matter in certain forms. 



The explanation which he gives is that the disinfecting action of chlorin 

 is not due merely to oxidation but also to the action of products formed 

 by its substitution for hydrogen in ammonia and organic compounds. 



EXPERIMENTS WITH BACILLUS TUBERCULOSIS 



In experiments upon the tubercle bacillus the method was as follows 

 Two and one-half cc. of disinfectant dilution were added to 2% cc. of a 

 suspension of culture (or a mixture of such suspension with an equal 

 quantity of horse-blood serum), and they were mixed thoroughly by 

 vigorous shaking. The suspension was made by rubbing up in sterile 

 distilled water enough of the surface growth from a bouillon culture to 

 give a suspension whose density was approximately equal to that of a 

 24-hour culture of Bacillus typhosus. After an exposure of 10 minutes 

 enough sterile sodium thiosulphate solution (or sodium sulphid where 

 mercuric chlorid was used) was added to insure complete neutralization, 

 and finally 1 cc. of each neutralized test mixture was injected subcutane- 

 ously into a guinea pig. 



