160 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 6 



and his associates. In general, this work has emphasized the 

 value of a series of compounds containing ' ' active chlorine, ' ' 

 by which term Dakin infers a connotation of "the ability of 

 any particular substance to part with chlorine, free or com- 

 bined, in such a way that it can effect the chlorination of bac- 

 terial and other proteins. ' ' Through the NH groups of their 

 constituent amino-acids the proteins are subject to attack by 

 such chlorinated agents, whereby in the first step the CI is 

 substituted for the H-atom in the group mentioned with the 

 formation of chloramines. 



Materials and Methods 



In the preliminary work here reported we have not departed 

 from the readily obtainable commercial products, namely, (1) 

 commercial chloride of lime, or "bleaching powder," (2) 

 "chlorinated potassa" (a liquid product recognized by certain 

 St. Louis manufacturers as "eau de Javel"), (3) solid sodium 

 hypochlorite, and (4) Dakin's soluble chloramine T. These 

 we have compared with a few standard disinfectants of other 

 groups. The commercial products vary somewhat in compo- 

 sition, but these differences, in our experience, are not so great 

 as to interfere with this type of practical work. A careful 

 study of standardized preparations is, however, planned. 

 Chloramine T, or chlorazene, is the abbreviated or trade name 

 for sodium-toluene-para-sulphochloramide. No experimental 

 work was done with the other Dakin products of this class. 



The chlorinated lime, designated 10 per cent, was prepared 

 in the following way: Ten grams of a standard commercial 

 product were stirred into 100 cc. distilled water. After stand- 

 ing 10 minutes the supernatant liquid was filtered and the 

 filtrate employed. Other concentrations were prepared in an 

 analogous manner. The commercial Javel water was used as 

 if it were a pure substance, 10 and 20 per cent solutions re- 

 ferring respectively to the use of 10 and 20 cc. of the commer- 

 cial product with enough water in each case to make 100 cc. 

 All necessary precautions have been taken to prevent acci- 

 dental contamination. The technique of handling treated seed 



