DISINFECTANTS AND ANTISEPTICS. 



Mercuric Chloride or Bichloride of Mercury. This 

 substance is probably more commonly used than any other 

 one disinfectant. In the strength of i-iooo it will some- 

 times kill the spores of anthrax within a few minutes (see 

 Bacillus anthracis, Part IV.). It is claimed that its affinity 

 for albuminous bodies, and the readiness with which it 

 combines with such substances, detracts from its value for 

 some purposes. On the other hand, many observers claim 

 that the albuminous combinations formed under such cir- 

 cumstances are soluble in an excess of albuminous fluid, 

 and that its value as a germicide is not affected thereby. 

 To obviate this possible difficulty it is customary in prac- 

 tice to combine the bichloride of mercury with some sub- 

 stance that will prevent the precipitation of the mercury 

 salt by albumin. For this purpose 5 parts of any one of 

 the following substances to i part of bichloride of mercury 

 may be used hydrochloric acid, tartaric acid, sodium 

 chloride, potassium 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. 



5 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 develop- 

 ing in a culture-medium containing 1-40,000. In combi- 

 nation, as potassio-mercuric iodide, it has been used in 

 soaps (McClintock) with very favorable results. The sub- 

 stance is not extensively employed, and further investiga- 

 tion 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 



