766 A MANUAL OF BACTERIOLOGY 



Extremely high values were at one time given for the 

 germicidal efficiency of corrosive sublimate. This is now 

 known to have been due to its powerful inhibitory action, 

 traces of the substance carried over into the subcultures 

 preventing growth (see p. 774). 



The Local Government Board recommended the following 

 solution of corrosive sublimate for disinfecting purposes : 



Corrosive sublimate ... | oz. 



Hydrochloric acid . . . . 1 oz. fl. 



Anilin blue . . . . . 5 gr. 



Water ...... 3 gals. 



This forms a solution of 1-900 nearly ; it would be prefer- 

 able to use 1 oz. of corrosive sublimate. 



The biniodide is also a powerful disinfectant when 

 dissolved in potassium iodide. It is not affected by 

 albuminoids nearly as much as is perchloride, and may 

 be incorporated with soap. 



Soluble silver salts are powerful disinfectants, weaker 

 than mercuric chloride, but far less sensitive to albu- 

 minoids ; in blood-serum, for instance, silver nitrate is 

 several times as powerful as corrosive sublimate. They 

 are incompatible with chlorides, except in certain organic 

 combinations, from which silver chloride is only partially 

 precipitated. Silver salts are poisonous, though less so 

 than those of mercury. 



Iron and zinc salts have been credited with useful 

 disinfectant action ; but, in fact, their value is very small, 

 and no practical account need be taken of them. A very 

 strong antiseptic power has been attributed to copper 

 salts, which, according to some experiments, exercise a 

 sufficient disinfectant action on sporeless organisms, such 

 as the B. typhosus, to enable drinking water to be 

 sterilised from such infections by the small quantity of 

 copper which it dissolves from a copper vessel (p. 724). 



