LICE ' 291 



affected. Consequently this treatment is not always fatal 

 to lice. Coal tar dips, however, have the advantage of 

 having antiseptic properties, hence the skin of the hog 

 when dipped in such a solution will be kept in good con- 

 dition. Kerosene emulsion may be used in the dipping 

 tank, but this is somewhat expensive and difficult to pre- 

 pare. 



One of the best solutions and one of the cheapest prep- 

 arations for destroying lice is crude oil. This may be 

 used by filling the tank nearly full of water and then 

 pouring a few gallons of oil into this. The oil will float 

 on the surface of the water. When hogs are driven 

 through and made to dive into this solution at one end of 

 the tank and swim to the other end and walk out they are 

 thoroughly covered with oil at all points. Oil in this form 

 also is not sufficiently strong to do any harm to the hog. 

 Furthermore, it will destroy all lice as well as the nits. 



A convenient arrangement of a dipping tank is shown 

 in the foregoing cut. The tank is set into the ground. 

 The available commercial tanks are usually made of gal- 

 vanized iron. Cement can also be used and is more dur- 

 able. The tank should be wide enough so that a hog 

 will not become wedged in and deep enough to allow the 

 hog to go completely under. The lower corner should be 

 cut off at both ends, thus making an incline where the hog 

 goes in and also where he comes out. A platform is built 

 at the end at which the hogs are to be driven in somewhat 

 higher than the level of the tank and an incline is made 

 from this platform into the tank. The lower end of this 

 incline should be at the surface of the liquid in the tank. 

 In order to get the hogs onto the platform a chute must 

 be built from the rear leading up to it. This as well as 

 the platform and the incline must be enclosed with a fence 



