222 CHEMISTRY OF FARM PRACTICE 



closed for not less than twelve hours. The temperature of 

 the room should not be less than 65 F. for the treatment 

 to be effective. It is well to sprinkle the floor and other 

 objects not harmfully affected by water, before the treat- 

 ment, as it is more effective in a damp atmosphere. 



Sulphur. Barns and other outbuildings may be more 

 cheaply but not as thoroughly disinfected with sulphur 

 fumes. These fumes bleach fabrics and discolor some paints, 

 for which reason their use is not always to be recommended. 

 Use not less than 4 pounds of sulphur to each 1000 cubic feet. 

 Break the roll sulphur into small pieces and put them into 

 an iron pot which should be set in a tub containing a few 

 inches of water as a preventive of fire. Pour alcohol on the 

 sulphur and ignite. If possible, keep the compartment closed 

 for twelve hours. 



Carbolic Acid. Carbolic acid or phenol (CeHsOH) has 

 been extensively used as a disinfectant for years. It is 

 poisonous and should be carefully handled. Pure carbolic 

 acid is a solid at ordinary temperatures and crystallizes into 

 long pink or white needles. It is often sold in the liquid 

 form, which is prepared by adding 1 part of water to 9 

 parts of the crystals. Carbolic acid used in the proportion 

 of 1 part of acid to 20 parts of water is a very effective 

 disinfectant. The carbolic acid is not readily soluble: 

 for this reason it should be carefully dissolved in warm water. 

 When garments are to be disinfected they should remain in 

 the solution prepared as directed above for not less than 

 one hour. 



Carbolic acid is poisonous, expensive and will destroy 

 the spores of anthrax and other spore-forming bacteria. It 

 has several advantages in that it destroys non-spore-bearing 

 bacteria, is little interfered with by albuminous matter, 

 when diluted does not destroy fabrics nor corrode metals, 

 and that it is easily obtained at any drug store. 



Crude Carbolic Add. Crude carbolic acid is very exten- 

 sively used as a disinfectant. It is variable in its composi- 



