DISINFECTANTS AND ANTISEPTICS. 1 99 



sium chloride, or ammonium chloride. A very practical stock- 

 solution for laboratory purposes has the following composition : 



Hydrochloric acid 100 c.c. 



Bichloride of mercury 20 grams. 



Five c.c. in a liter of water makes a solution of about i-iooo strength. 



Mercuric Iodide. — An extremely high antiseptic value has 

 been placed on this substance by Miquel, who claims that the 

 most resistant spores are prevented from developing in a culture- 

 medium containing 1-40,000. In combination, as potassio- 

 mercuric iodide, it has been used in soaps (McCHntock) with 

 very favorable results. The substance is not extensively em- 

 ployed, and further investigation is necessary to determine its 

 true value. 



Attempts are being made to manufacture combinations of 

 mercury and other powerful metallic germicides with organic 

 acid and basic bodies, the purpose being to utilize the metallic 

 base in greater strength without injury to the living tissues. 

 Such compounds are exemplified by mercurol, said to be a com- 

 bination 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 posi- 

 tion to the bichloride of mercury in germicidal 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 1-10,000 solution is required 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 limited. In the solutions usually employed for douching the 

 cavities of the body the available silver nitrate is imm.ediately 



