FAULTY CONFORMATION 123 
cooler and more humid atmosphere of winter. It is inter- 
esting to note, too, that an alternation of humidity and dry- 
ness is far more liable to injure the quality of the horn and 
tend to its contraction than the long-continued effects of 
dryness alone. A common illustration of this is to be 
found in the effects of the ordinary poultice. Everyone 
knows that when, after a few days’ application, they are 
discontinued, we get as a result an abnormally dry and 
brittle state of the horn. This is doubtless due to the 
poultice removing the thin, varnish-like, and protective 
pellicle known as the periople, and thereby allowing the 
process of evaporation to act on the water normally con- 
tained in the hoof. 
Exciting Causes of Contraction.—Among these, first place 
must undoubtedly be given to shoeing. This does not 
necessarily imply shoeing inore than ordinarily faulty, nor 
a faulty preparation of the foot, but shoeing as it is gener- 
ally practised. No ordinary shoe, except a few devised for 
the purpose, such as the Charlier or the tip, allows the frog 
to come in contact with the ground. This we take to be 
the main factor in the causation of contracted heels, especi- 
ally with a predisposition already present in the foot itself. 
In the words of Lungwitz: ‘Regarded from this point of 
view, there is no greater evil than shoeing. It abolishes 
the necessary counter-pressure, and thus interferes with 
expansion. Bars, sole, and frog cannot perform the func- 
tions that naturally belong to them as they would do with- 
out the shoe.’ 
In addition to the evil of the shoe itself, errors of prac- 
tice in the forge contribute to the causation of contraction. 
Taking first the preparation of the foot, we find that often 
the heels are lowered far too much, and the toe allowedto 
remain too long. This can have but one effect—that of 
throwing a greater proportion of the animal’s weight upon 
the heels than properly they should bear, with, what we 
now know to be the consequence of that, a corresponding 
pushing inwards and downwards of the horn; in other 
words, contraction. 
