AS TO SOUNDNESS. 55 
of the horse it invariably leaves behind it permanent and 
observable pathological changes, such as alterations in 
shape, and in quality of texture of the horny box, or it 
leaves a badly balanced vascular system within this 
structure. ‘The altered physical conditions of the horny 
box are— 
1. Laminated, shelly, diverging rings round the hoof. 
2. Diminished convexities of sole. 
‘There are others, but these are the most constant and 
obvious. Should the feet we are now considering have 
these two altered conditions, of course we have no doubt 
in condemning the horse as unsound. Suppose we have 
sound-looking feet, no matter of what size, we can at all 
times test their vascular system by a battering canter on 
ahard road. This will tax the capacities of the vascular 
mechanism to its utmost, and it is only a vascular 
mechanism that has never been damaged that can, after 
such an ordeal, immediately resume a quiescent state. 
After the canter tie up the horse in a cool shade for 
twenty minutes, then trot him slowly in hand. If he has 
had inflammation in his feet you will now find that he 
‘goes on his heels and picks up each foot as soon as he 
puts it down, or, as horsemen say, he will go “‘feely, like 
acat on hot bricks.’’ You will all, no doubt, have ex- 
-perienced the painful and highly unpleasant jar or sting 
when leaping from a height and alighting flat on your 
feet when they are hot andswollen. The horse no doubt 
feels this on moving, and this is why he goes on his heels: 
