DESTRUCTION OF. BACTERIA. 23 



min. It is liable to rust iron and steel. It is suitable 

 for the disinfection of urine, sputum, feces, and albu- 

 minous discharges. It is not a good skin disin- 

 fectant because it hardens the skin and in some cases 

 will cause a dermatitis. 



Bichloride of mercury is of limited usefulness 

 because it is a corrosive poison, corrodes all metals, 

 and coagulates albumin. This last action renders it of 

 little use for the disinfection of sputum, feces, or pus. 

 On the other hand, it is excellent for disinfecting 

 floors, walls, and furniture; that is, surface disinfec- 

 tion. In the strength of i : 1000 it kills bacteria in a 

 half an hour, but for spores a i : 500 solution must be 

 used. It is widely used for skin disinfection; for this 

 purpose a 1 : 1000 solution is sufficiently strong. On 

 account of the poisonous property of bichloride solu- 

 tions it is safer to add coloring material to prevent any 

 possibility of their being drunk by mistake. 



Carbolic acid is suitable for the disinfection of 

 intestinal discharges, sputum, urine, floors, furniture, 

 soiled linen, and clothing. It will coagulate albumin, 

 but its action is not interfered with to) so> great an 

 extent as is the case with bichloride, of mercury. 

 Cresols, chemical substances closely related to carbolic 

 acid, are more powerful and not so poisonous. They 

 may be used in 5 per cent, solution. 



Chlorinated lime is a deodorant as well as a dis- 

 infectant, both properties being dependent upon the 

 liberation of chlorine gas in the presence of moisture. 

 It is most widely known a.nd used for the disinfec- 



