332 BACTERIA 



way into the law courts, owing to cumulative poisoning, and 

 it should only be used with the very greatest care as a food 

 preservative. 



Carbolic acid has come into prominence as an antiseptic 

 since its adoption by Lister in antiseptic surgery. It is 

 cheap, volatile, and effective. One part in 400 is antiseptic, 

 and I in 20 germicidal. As a wash for the hands the former 

 is used, and a weaker solution for the body generally. Car- 

 bolic soap and similar toilet combinations are now very 

 common. At one time it appeared as if corrosive sublimate 

 would oust carbolic from the first place as an antiseptic 

 solution, but a large number of experiments have confirmed 

 opinion in favour of carbolic. Professor Crookshank found 

 that carbolic acid, i in 40, acting for only one minute is 

 sufficient to destroy Streptococcus pyogenes, S, erysipelatis, 

 and Staphylococcus pyogenes aureus, and in the strength of i 

 in 20 carbolic acid completely sterilised tubercular sputum 

 when shaken up with it for one minute. 



Creosol, a member of the phenol series, is a good disin- 

 fectant, and the active element in lysol, Jeye*s fluid, creo- 

 Hne, izal, and creosote. 



Sulphurous acid is one of the commonest disinfectants 

 employed for fumigation — the old orthodox method of dis- 

 infecting a room in which a case of infective disease has 

 been nursed. It is evolved, of course, by burning sulphur. 

 For each thousand cubic feet from one to five pounds of 

 sulphur is used, and the walls may be washed with car- 

 bolic acid. Dr. Kenwood carried out some experiments 

 in 1896' which appear to support the disinfecting power 

 of sulphur fumes. He found that the Bacillus diphtherice 

 was not killed, though markedly inhibited, when the sul- 

 phurous gas (SO3) did not much exceed .25 per cent. 

 But the bacillus was killed where the sulphur fumes ex- 

 ceeded .5 per cent. Both these results had reference to the 



* British Medical yournal, 1896 (August), p. 439. 



