MEANS OF DEFENCE AGAINST MICROBES. 255 



tliis latter dose is a maximum which it iq almost 

 impossible to exceed in man in the course of twenty- 

 four hours without poisoning him. 



Sulphurous acid is very effectual when employed 

 in fumigations, but it does not penetrate to the interior 

 of the tissues, and only acts on the microbes on theii- 

 surface. It dof s not destroy their spores. 



Iodine has great effect in this respect. Davaine 

 has ascertained that seven milligrammes of iodine 

 suflBce to destroy the bacteria of anthrax in a litre 

 of liquid. Instead of a hot iron, tincture of iodine 

 might, therefore, be used to cauterize the bites of 

 poisonous flies, carbuncles, and the pustule of anthrax. 



Koch states that a solution of five per cent, of 

 carbolic acid is required to destroy the spores of 

 anthrax in twenty -four hours ; but the bacilli them- 

 selves are destroyed by a solution of one per cent. 

 A solution of 02 per cent, iodine, or 007 per cent, 

 of bromine prevents the development of bacilli. 



Chloride of zinc and sulphate of iron, which have 

 been recommended as disinfectants, are very inferior 

 to chloride of lime, which takes the third place in the 

 list, the second being occupied by chlorine. 



Alcohol arrests the development of bacteria and 

 their spores, but does not destroy the latter, even 

 at the end of a month, as it is stated by Claude 

 Bernard. 



Babfes regards essence of mustard as an excellent 

 preservative from cholera. If a drop of this essence 



