Oct. us. 1920 Germicidal Value of Some Chlorin Disinfectants 



89 



into tubes of standard broth. The mixtures were thoroughly shaken just 

 before subcultures were made. 



In these experiments and in all others described in this paper, the test 

 mixtures were used at ordinary room temperatures. 



The results of experiments 2 and 3 are given in Table II. 



Table II. — Germicidal efficiency of chloramin T against Staphylococcus aureus, Bacillus 

 typhosus, and B. pyocyaneus when mixed with an equal quantity of blood serum before 

 culture is added a 



EXPERIMENT 2 



a + Signifies growth; — , no growth. 



Experiments 4 and 5. — These were preliminary experiments with 

 Dakin's solution, which was made up by the use of sodium carbonate 

 alone, as described in the first of the methods of preparation previously 

 mentioned. In order to determine what influence the boric acid exerts, 

 two portions were tested, one with and the other without the addition 

 of boric acid. The technic was the same as that described for experi- 

 ments 2 and 3. Dilutions given are based on the amount of sodium 

 hypochlorite. The results of these experiments are given in Table III. 



The results given in Table III indicate that the boric acid adds some- 

 what to the germicidal power of Dakin's solution. This is probably due 

 to the small amount of hypochlorous acid set free by the boric acid. 



Experiments 6, 7, and 8. — These experiments were made in order to 

 compare the germicidal powers of chloramin T and Dakin's solution 

 against Staphylococcus aureus, Bacillus pyocyaneus, and B. typhosus. The 

 technic was the same as that described for experiments 2 and 3, except 

 for the omission of the 15-minute exposures. The results are given in 

 Table IV. 



