320 
EXPERIMENTS ON THE 
In light horses this downward and backward action of the foot is, 
I conceive, very slight; but I consider that it should be accommo¬ 
dated, although a great difficulty exists in carrying it out prac¬ 
tically in all cases. Again, how common a remedy is it in navi¬ 
cular disease to apply tips to a horse and blister him round the 
coronet, and it is, I consider, a good practice, and many horses 
become relieved, or continue sound after this treatment. How can 
this apparent invitation to a bruising of the already inflamed navi¬ 
cular joint be reconciled, except it may be that we restore by the 
tip the slightly yielding downward and backward action of the foot, 
and thus relieve the concussion] What surprising changes take 
places in the feet of horses wearing tips! After a few months we 
often find feet which before were dry, and harsh, and brittle, 
become of a totally different character—tough and elastic, and 
almost oily, as you cut the hoof: also the rapid disappearance of 
thrushes. This can only be accounted for, I conceive, by the fact of 
the different parts of the foot having been brought into natural 
healthy exercise. Again, how can we account for the hoof becoming 
wider at its posterior part, under particular states of shoeing, 
except that it is by allowing parts to be brought into action which 
were before fixtures ] As when a man’s arm is confined in a sling 
it wastes away, but when it is again brought into use the muscles 
increase in size, so the width of the foot is thus often increased 
under the use of tips, one-sided nailing, springing of the heels and 
bar shoes, and elastic materials interposed between the shoe and 
the foot. Tips, and turning out the animal upon moist land, soon 
effect a change in the size of the foot, although on a return to the 
former condition of shoeing and stabling, rapid changes again take 
place. 
18 th Experiment , 
On the dead fore foot of a cart-horse, cut off at the small pastern. 
A portion of horn at the crust was left isolated by making a deep 
furrow on each side of it, in the direction of the laminae, and re¬ 
moving the attachments to the horny sole, as also to the coronet. 
I wished to ascertain how the laminae seemed to acton the isolated 
portion. 
Result .—I could find that this piece of horn was very readily 
moved transversely ; but when it was pressed from below upwards, 
very little motion indeed could be produced by the strongest pres¬ 
sure : the whole force of the hand seemed to convey an impression 
as if there were, at first, the least possible degree of yielding; 
then, as if no amount of force could produce any effect whatever. 
Whilst applying pressure from below, and viewing the coronet, 
