36 



greater convenience or other circumstances, to use one or more 

 of these, iu place of those means ah'eady mentioned. Among the 

 large number of such substances are carbolic acid or similar 

 preparations, corrosive sublimate, chloride of lime, sulphur fumes 

 or chlorine gas. 



Carbolic acid is a cheap, effective disinfectant, but, owing to its 

 caustic nature, must be used with care, to avoid accidents. The 

 strong acid brought iu contact with the skin quickly destroys it. 

 All solutions, whether weak or strong, taken internally in consid- 

 erable quantities are irritating and poisonous. 



Carbolic acid is sufficiently soluble in water so that a five per 

 cent solution may be made. If more than one part of acid is 

 added to twenty parts of water, the excess remains in suspension 

 as pure acid. A five per cent watery solution is sufficiently strong 

 to destroy most germs inside of one hour, provided the organisms 

 are kept continually moist with it. A solution of this strength 

 is not caustic, but so irritating that with most persons it will at 

 first cause tingling and later numbness of the hands or other parts 

 of the body with which it may come in contact for any length of 

 time. A five per cent watery solution may be used for the disin- 

 fection of walls, floors, mangers, harnesses, excrement, offal, etc. 

 For use upon floors and walls it may be applied economically by 

 means of a pump ; preferably such a one as is employed for 

 spraying fruit trees. Thrown in a fine spray against the walls, it 

 penetrates into all the cracks and crevices. There is little danger 

 in using a five per cent solution about mangers or feed troughs if 

 they are allowed to become thoroughly dry before being used. 



Carbolic acid solutions are particularly effective for ridding 

 stables, pig pens and hen houses of lice and other parasites. One 

 part of acid and twenty or thirty parts linseed oil makes an excel- 

 lent mixture for application to the skin of animals harboring lice 

 or other animal or vegetable parasites. 



For disinfecting soils, manure heaps or bodies of animals, 

 stronger mixtures than five per cent solution may be used. Crude 

 acid is suitable for all disinfecting purposes of buildings, but only 

 the better grades should be applied to the bodies ofliving ani- 

 mals. 



To increase the efficiency of carbolic acid as a disinfectant, some 

 advise the use of sulphuric acid in combination with it. The 

 United States Department of Agriculture a few years since recom- 

 mended the use of the following mixture, and gave these directions 

 for its preparation and use : — 



