86 MI;TIK>I)S or STKKILISATION 



aiound tin- M itches, a circuinstance sufficient to account for the bad repute in 

 \\hich wort- and beer droppings an- held. Disinfection experiments have, 

 however, >hcN\ 11 that these gei m> can be killed by exposure to the action 

 assisted by careful brushing of a chloride of time solution containing i percent. 

 of active chlorine. As g..od commercial chloride of lime yields 30-35 per cent . 

 of chlorine, (ho solution may In- prepared for use by mixing 3-3! kilos. (6.6-7.7 

 11)-.) of the chloride with i hectolitre (22 gallons) of water i.e. about 5 ox. per 

 gallon Mirring the mixture up frequently, and, after settling, pouring off the 

 clear liquid from the (useless) sediment. According to R. Koch, 0.2 percent, 

 chlorine- water will kill the spores of 1',. a nflu-iicis within an hour. Kxhaustive 

 conducted chiefly from a medico-hygienic point of view on the 

 anti-bacterial properties of chlorine and bromine have been carried out by 

 I'.i i:\iiAiii) KISCIIKH and \\. PHOSKATKK (I.). 



Among the inorganic acids, hydrofluoric acid and its alkali salts have proved 

 to be particularly pO18OnOU8 to bacteria. In the last few years this MI!I. 



. by the labours of Ktlront, been utilised in distilleries; on this head more 

 detailed repoi ts will he given in a later section. 



Boric acid, either jmr se or in the form of borax, is occasionally in despite 

 of prohibitory regulations- u>ed for preserving food-stuflfe (c.t/. milkj. A p r 



-ible ami useful application of this substance may he made in the preparation 



a paste by employing an aqueous solution of borax as a substitute for 



\\ater. PaMe prepared in this way can be recommended, for instance, for 



allixing the labels on wine bottles kept in store, the occurrence of the uncleanly 



formation of mould, otherwise intervening, being thereby prevented. 



The effect of ozone and hydrogen peroxide on bacteria is due to a common 



cause, vi/.., the decomposing power of the oxygen liberated. Accoiding to the 



determinations made by H. SoNNTAG (I.), ozone has only a weak germicidal 



power, but other experimenters, c.t/. OBKKDOKITKK (I.) and WY>MK<>U rr-< n (I.), 



obtained ><>mewhat more favourable results. According to the research* 



( hi i. MI I.LKK (I.), this gas acts more powerfully when it is passed, along with 



oxygen, through the culture. When the volume of the liquid amounted to 



500 c.c. an ozone-content of 90 m.grms. of 3 per 100 c.c. of the gas was requisite 



in order to kill the germs of the spores of anthrax bacillus present. According 



to the researches of Cinn ST. MAS (L), the germicide power of ozone sinks to nil 



when its amount falls below 0.05 per cent, by volume; so that no effect can be 



cipated from the much lower proportion (iio m.grms. per 100 litres) of 



t iii the atmosphere. With regard to the purification of river water 



-intended for drinking purposes by the aid of ozone, prepared artificially on 



a 1.. an exhaustive report h;ts been drawn up by E. VAX EI;MI:M.I;M (I.). 



Owing to th> expense entailed, the utilisation of the anti-bacterial 



f hydrogen peroxide in the service of the fermentation industry 



nil j'i at -tic-able. The invention of a less expensive method of production 



would, however, ensure it an extensive sphere of operation, since this bacterium 



the advantage that during its action it is resolved into water and 



When the latter has killed the organism, nothing is left of the anti- 



ic hut harm'. . < Advantage might be derived from this property 



in connection with the manufacture of conserves; but hitherto its value 



not seem to have been sufficiently appreciated. A few experiments have, bow- 



i. been made with it in connection with the fru-ing of drinkii :'rom 



germs. In partial improvement on the results reported hv Van Tromp. it has 

 been proved by AI.I 1:1101:1 T.K (I.) and P. Srim.ow (I.) that an addition of i part 

 per -in if of H^O, to drinking water will, within twenty-four hours, be fatal to 

 the common (innocuous) water bacteria, the microbes usually present in conduit 



which produce cholera and typhus. No alteration in 



