90 MI.TIIODS or STKKII.ISATION 



us at the end of several weeks. AK<>NS>\ (1.) found that typhus bacilli, 

 ttccus pyogenes aureus, and /!. n nth runs could not develop in bouillon 

 continuing one-twentieth put par mil of tin's aldehyde. According to the 

 .MIL (I.) :md of E. VAN KnMi \,i M a nd SUGG (I.), the spores of 

 ,ud those (very tenacious of life) from garden soil were killed by an 

 exposure of one hour to the influence of a i jw ///il 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) p ive 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 

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

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

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

 TKILLAT (II.) gives a few methods for testing its strength :m<l 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 nuans K. II. LKHMANN (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. CAMIUKK and 

 A. BROCHET (I.) recommend a burner, and B. TOLLENS (T.) 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. BROCHET (t.) 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 

 di scribed by A. DIEUDONNK (11.), 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. 

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

 similar H<n-i>',-\>nn coli comiifnf, which, in the bacteriological analysis of water, 

 i- 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, ai.d 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 

 :';iined by KID. AUKL (1.). 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 ye; 

 b-h bhifl disii. frt ant. Iii this connection it has been established by 



W. \ViM'isrn (I.) that yeast cells show much less susceptibility; consequently 

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

 they are readily a fleeted by tin- influence of hot water vapour, chloride of lime, 



o that there is no lack of available remedies. 



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

 the result that this compound was found not to injure (kill) bacteiia. except in 

 the M when iodine was liberated. In all otlx r instances (which thus 



