2OO MANUAL OF BACTERIOLOGY. 



the metallic base in greater strength without injury to the 

 living tissues. Such compounds are exemplified by uicr- 

 curol, said to be a combination of mercury with nucleinic 

 acid, and to possess active germicidal properties, great 

 penetrating power and no injurious effect on living tissue. 

 It is also said to have a particularly destructive action upon 

 the gonococcus. 



Silver Nitrate. This salt probably occupies the next 

 position to the bichloride of mercury in disinfectant power. 

 Behring claims it to be superior to bichloride of mercury 

 in albuminous fluids. The anthrax bacillus is killed by a 

 solution of 1-20,000 after two hours' exposure. At least 

 forty-eight hours' exposure to a i-i 0,000 solution is re- 

 quired to kill the spores of anthrax. It is very irritating, 

 and possesses strong affinities for chlorides, forming with 

 them, insoluble chloride of silver, a salt without germicidal 

 value. For these reasons the use of silver nitrate is lim- 

 ited. In the solutions usually employed for douching the 

 cavities of the body, the available silver nitrate is imme- 

 diately converted into the insoluble chloride, and little if 

 any germicidal action takes place. To this fact may be 

 ascribed the varying clinical results reported. 



Many semi-proprietary silver compounds are on the mar- 

 ket, introduced to replace the nitrate and its objection- 

 able features. The most important are argentamin, ar- 

 gonin, protargol and argyrol, all organic silver combina- 

 tions. They do not combine with chlorides, are less irritat- 

 ing than the nitrate, and, not coagulating albumin, they pos- 

 sess greater penetrating power. Clinical reports and in- 

 vestigations have been so contradictory thus far that their 

 value cannot be readily estimated. 



Carbolic Acid. One of the most important and most 

 widely-used disinfectants. It is usually employed in 

 strengths of from i to 5 per cent. A 3 per cent, solution 



