SOLUTIONS AND STAINS 35 



this standard solution is equivalent to 0.00372 gram of 

 sodium hypochlorite. 



TITRATION OF BLEACHING POWDER. Bleaching powders 

 /ary considerably in their "available chlorine" content, so 

 hat it is desirable to determine the available chlorine in each 

 arge batch. Bleaching powders with less than 20 per cent, 

 ivailable chlorine should be rejected. Exceptional samples 

 nay contain as high as 35 per cent, available chlorine. 



The available chlorine content may be determined as follows: 

 exactly 10 grams of bleaching powder made up of small 

 Camples from different parts of the jar, in order to obtain a 

 epresentative sample, are well shaken with a liter of water. 

 \fter standing about six hours the solution is filtered and a 

 [o c.c. sample of the filtrate is titrated in exactly the same 

 nanner as in the titration of Dakin's solution. In this case 

 he number of cubic centimeters of decinormal thiosulphate 

 equired to decolorize, multiplied by the factor 3.55, gives the 

 percentage of active chlorine in the bleaching powder. 



OTHER CHLORINE ANTISEPTICS. 



Antiseptics of the chlorine group when properly applied 

 mve proved to be the most efficient antiseptics used in the 

 >resent war. We are indebted to Dakin for two other impor- 

 ant chlorine antiseptics: 



" CHLORAMiN-T. 1 Chloramin-T is the abbreviated name 

 ior sodium-toluene-sulphon-chloramin. Chloramin-T is sol- 

 uble in water and can be used in stronger solution (up to 2 

 )er cent.) than the hypochlorites. It is more stable and 

 txerts more prolonged action than hypochlorite when acting 

 n the presence of much blood. It is not toxic and is less 

 rritating than the hypochlorites, but it has but little solvent 

 .ction on necrosed tissue. It is well suited for use on wounds 

 reviously cleansed with hypochlorites, and in suitably dilute 



1 Dakin and Dunham: Hand-book of Antiseptics. 



