Germicidal action

Sulfides, thiols, and proteinacious organic matter, particularly plasma and whole blood, seriously depress and may even aboHsh the germicidal action of mercury compounds (qv). As of this writing approved uses for mercurials are limited to contact lens cleaning fluids, spoilage prevention of stored... 

S. Rideal noticed the peculiar effect of ammonia on the germicidal value of hypochlorites he said that the first rapid consumption of chlorine is succeeded by a slower action which continues for days, and that the germicidal action continues after free chlorine and hypochlorite have disappeared it appeared that ammonia substitution products are formed yielding compounds more or less germicidal. 

J. Race, attempting to make ammonium hypochlorite by the double decomposition of ammonium oxalate and calcium hypochlorite, obtained a soln. with its germicidal action greatly enhanced and it was assumed that the unstable ammonium... 

Anionics are the most widely used surfactants on account of cost and performance. Cationics are expensive, but their germicidal action makes them useful for some applications. An advantage enjoyed by non-ionics is that the lengths of both hydrophilic and hydrophobic groups can be varied. 

Ultra-violet light, such as that emitted by a mercury-vapour lamp, exerts a powerful germicidal action on water and ice. In a series of experiments earned out at Marseilles it was observed that a lamp working with 3 amperes at 220 volts destroyed pathogenic organisms in water within a radius of 2 inches in two seconds.2 In order to ensure complete sterilisation m a stream of water, the latter is made to flow, by... 

The efficiency of the process appears to be independent of the amount of dissolved oxygen, the germicidal action being a purely physical action not involving the production either of hydrogen peroxide or of ozone. 

Alkalies are also powerful germicides. The addition of hme to water in accordance with Clark s process for removing temporary hardness effects the removal of the bulk of the contained bacteria.1 This is largely due to the mechanical effect of sedimentation which causes the bacteria to be carried down with the lime, only a portion of them being killed. After a time they rise again into the water. By addition of excess of hme, the germicidal action is increased, but even with 0-2 per cent, of hme (calculated as CaO) or 20 parts per 10,000, the sterilisation is not usually complete,5 whilst at this concentration the water is too strongly alkaline for most purposes. 

In one case severe ulceration of the anterior ventral surface of the tongue was caused by ill-advised cautery of a small ulcer with a silver nitrate stick (37). Only silver nitrate solutions of 5-10% should be used to cauterize mucous membranes or when a strong germicidal action is desired. 

The mechanism of the germicidal action of ethylene oxide probably involves the alkylation of functional groups in nucleic acids and proteins by nucleophilic opening of the oxide... 

Chlorine and chlorine-releasing compounds have been used in the disinfection of water supplies for more than a century. The di.scovery that hypochlorous acid (HCIO) is the active germicidal species that is formed when chlorine is dissolved in water led to the development and use of the first inorganic hypochlorite salts such as NaOCI and Ca(OCI) . Later, organic Af-chloro compounds were developed as disinfectants. These compounds release hypochlorous acid when dissidvcd in water, especially in the presence of acid. Two equally plausible mechanisms have been proposed for the germicidal action of hypochlorous acid the chlorination of amide nitrn-... 

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