DISINFECTANTS OF THE CHLORIN GROUP 115 



Or it may be that the extra bonds of the nitrogen in the imino 

 group is utilized : 



R R 



HC NH 2 H C NH 2 



C=O+Cl2 = C=0 



I I/H 



NH N^-C1 



I I X31 



H C COOH H C COOH 



I I 



R R 



according to this explanation hypochlorous acid may react without 

 decomposing into chlorin: 



R R 



H C NH 2 H C NH 2 



C = O + HOC1 = C = O 



I I/H 



NH N^-H 



| | \0-C1 



H C COOH H C COOH 



I I 



R R 



In any case the chemical and physical properties of the protoplasm 

 would be so changed as to be incompatible with the life processes of 

 the microorganisms. 



Compounds containing the group NCI belong to the class of 

 chloramins. Their chlorin is still active and they are themselves 

 active germicides. Such compounds have been studied thoroughly 

 by Dakin who used them extensively in the disinfecting of wounds 

 in the great European war of 1914-18. 



Chlorinated lime, or bleaching powder, may be taken as a type 

 of the chlorin disinfectants. Its precise chemical composition is 

 not known although calcium oxychlorid (CaOCl 2 ) is now generally 

 accepted as being the essential agent of dry bleaching powder and 

 calcium hypochlorite (Ca(OCl) 2 ) to be the active germicide of the 

 solution. Although the reactions which occur are quite complicated, 

 it is certain that the active substances are nascent oxygen, chlorin, 

 and hypochlorous acid, and are probably formed as follows : 



2CaOCl 2 = Ca(OCl) 2 + CaCh 



Ca(OCl) 2 + H 2 CO 3 = CaCOs + 2HOC1 



2HOC1 = 2HC1 + O 2 



2HOC1 = H 2 O + C1 2 + O 



The substance is extensively used in the disinfection of sewage, 

 outhouses, cellars, and for miscellaneous purposes. Since 1908 it 

 has been used rather extensively in water purification. In practice 



