STERILIZATION — ANTISEPSIS — FOOD PRESERVATION 79 



(antisepsis) as in preventing microbic development in dead 

 organic matter (food preservation). 



Of the physical antiseptics, desiccation and cold are perhaps 

 of greatest importance. These agencies find apphcation to the 

 living body as well as in preservation of dead material. Sub- 

 stances which increase osmotic pressure/ sodium chloride and 

 sugar, are also employed to prevent microbic growth in foods. 



The chemical antiseptics are very numerous. In general 

 a germicide in higher dilution exhibits antiseptic effect. Small 

 quantities of the inorganic acids, hydrochloric, nitric, sulphuric 

 or sulphurous acid, prevent bacterial growth. Even boric acid, 

 which has little or no germicidal effect, will delay or inhibit 

 microbic development. Many organic acids possess inhibitive 

 properties toward bacterial action. Acetic and lactic acids 

 probably act merely by virtue of their acidity. Benzoic and saU- 

 cylic acids seem to be more antiseptic, probably by virtue of other 

 structural features in their molecules. Other organic substances, 

 such as phenol (carboUc acid) and formaldehyde in high dilu- 

 tions prevent or delay bacterial growth, and weaker germicides 

 such as alcohol, chloroform or ether, are fairly effective preserva- 

 tives. Oxidizing agents often decompose too rapidly to be of 

 much value as antiseptics. Iodine, however, is one member of 

 this group having considerable antiseptic value. 



Of the inorganic salts, mercuric chloride is most important. 

 Small quantities of this agent inhibit the multiplication of bac- 

 teria. It is extensively employed in antiseptic treatment of 

 wounds. The borates, nitrates and saUcylates, the latter com- 

 pounds of an organic acid, also inhibit bacterial action to some 

 extent. 



In using these substances as antiseptic applications to wounds, 

 the possible poisonous effects upon the body as a whole from 

 absorption of the antiseptic must be kept in mind. Moreover, 

 such substances ought not to be used as food preservatives with- 

 out due regard to the changes they may induce in the food and 

 the possible effects they may exert upon the consumer. 



