292 SWINE 



sufficiently high that the hogs cannot jump over. The 

 sides of the tank also should be provided with boards that 

 the liquid cannot slop over so easily. 



After pigs have been driven through such a tank once, 

 they become wise and are more difficult to take through a 

 second time. In order to facilitate matters a trap door is 

 arranged on the top of the platform. This is hinged at 

 the point where the platform meets the in-line. At the 

 front of this incline where it meets the solution is a wide 

 board or door hinged at the top to prevent the hog from 

 seeing what is ahead. Thus after the hog is driven onto 

 the platform, and he walks far enough forward, the trap, 

 which should be made of hard wo'od laid lengthwise so as 

 to make it slippery, will go down in front and allow the 

 hog to slide into the tank. The board in front will pre- 

 vent him from jumping across and will also allow him to 

 slide into the solution head first and without injury to 

 himself. If he should jump against this and throw it 

 forward, the attendant may stand at the side and hold it, 

 thus allowing the hog to slide into the solution quietly 

 and without injury. The hog should go in head first, take 

 a dive, and then swim through to the other end, where 

 there is an inclined board with cleats which will allow 

 him to walk up and out easily. This is also arranged with 

 a drain board to catch the liquid that runs off the hog and 

 allow it to run back into the tank. The lower part of the 

 tank is connected with a tile drain to draw off the water 

 in case it rains, thus preventing the oil from running off 

 at the top; also when the tank becomes dirty, the liquid 

 may be easily drawn off and the dirt shoveled out. 



Another means of helping to keep hogs free from lice is 

 by keeping their habitations clean because the pens also 

 usually afford lodging places for lice and nits. All rub- 



