90 METHODS OF STERILISATION 



germs at the end of several weeks. AROXSON (I.) found that typhus bacilli, 

 Staphylococcus pyogenes aureus, and B. anthracis could not develop in bouillon 

 containing one-twentieth part per mil of this aldehyde. According to the 

 researches of J. STAHL (I.) and of E. VAN ERMENGEM and SUGG (I.), the spores of 

 B. anthracis and those (very tenacious of life) from garden soil were killed by an 

 exposure of one hour to the influence of a i per mil solution of formaldehyde, 

 and a solution containing i part in 750 proved fatal to the germs in a quarter 

 of an hour. This disinfectant is therefore on a par with the strongest mineral 

 (bacterium) poison, corrosive sublimate, as regards efficiency, and surpasses it in 

 point of general applicability. Moreover, unlike the mercury salt, formaldehyde 

 is but slightly dangerous to man and the higher animals. The air may be im- 

 pregnated with sufficient of the vapour for the purpose of disinfection without 

 causing any greater inconvenience than coughing, which, however, soon dis- 

 appears, since one quickly gets acclimatised to this reagent. Formaldehyde is 

 generally met with in commerce as a 40 per cent, solution known as formalin. 

 TRILLAT (II.) gives a few methods for testing its strength and disinfecting 

 value. A few pads of cotton-wool or kieselguhr, &c., are moistened with the 

 liquid formalin and transferred to a box or other receptacle, wherein the articles 

 to be disinfected (clothing) are suspended ; or the same are laid between linen 

 cloths moistened with the liquid. By this means K. B. LEHMANN (I.) thoroughly 

 disinfected a complete suit of men's clothing, even when infested with anthrax 

 bacilli, by the aid of 30 grams (a fraction over i oz.) of formalin in twenty-four 

 hours. For the preparation of formaldehyde on a small scale R. CAMBIER and 

 A. BROCHET (I.) recommend a burner, and B. TOLLENS (I.) a lamp, both fed 

 with methyl alcohol. In the latter apparatus a dome or cap of platinum gauze 

 (2 cm. high and i cm. wide) is placed over the slightly projecting lighted wick, 

 and as soon as the gauze is red hot the flame is extinguished, whereupon the 

 formation of formaldehyde goes on uninterruptedly. It should not be forgotten 

 that as pointed out by A. BROCKET (I.) this incomplete combustion of methyl 

 alcohol also produces some 3 to 5 per cent, of carbon monoxide. An apparatus 

 constructed by Krell, and resembling the Barthel soldering-lamp, has been 

 described by A. DIEUDONNE (II.), by means of which a constant current of form- 

 aldehyde vapour can be produced from methyl alcohol and blown into crannies 

 and corners that require disinfecting. The different degree of susceptibility 

 exhibited by the various bacteria towards this poison has been utilised by E. 

 SCHILD (I. and II.) for the differentiation of typhus bacilli from the very 

 similar Bacterium coli commune, which, in the bacteriological analysis of water, 

 is both very important and difficult. The latter species develops freely in a 

 bouillon containing i part of formaldehyde in 7000, whereas the former will not 

 do so. Therefore, if a species of fission fungus isolated from the sample of 

 water, and suspected to be typhus bacillus, produces turbidity in such a medium, 

 this behaviour shows that it is not the bacillus which causes typhus. The 

 applicability of this method which gives a negative characterisation has been 

 confirmed by RUD. ABEL (I.). The researches above noticed deal only with the 

 action of formaldehyde on bacteria, but for the fermentation industry it is also 

 important to know how the higher fungi, and especially the alcohol yeasts, 

 behave towards this disinfectant. In this connection it has been established by 

 W. WINDISCH (I.) that yeast cells show much less susceptibility ; consequently 

 this aldehyde is not a suitable means for killing them. Fortunately, however, 

 they are readily affected by the influence of hot water vapour, chloride of lime, 

 &c., so that there is no lack of available remedies. 



The antiseptic power of iodoform, CI 3 H, was studied by BEHRING (I.), with 

 the result that this compound was found not to injure (kill) bacteria, except in 

 the rare cases when iodine was liberated. In all other instances (which thus 



