THE HORSE. 



29 



they simply produce the horny lamella 

 arranged along its interior; as one proof 

 of which, the wall measures as much in 

 thickness at the place where it quits the 

 coronet as it does at any point lower down. 

 Other demonstrations of this fact come 

 every day before such practitioners as have 

 to treat canker, qmttor, sandcrack, and 

 other diseases of the feet. 



" The horny sole is a production from the 

 villi of the sensitive sole ; after the same 

 process as that by which the horny frog is 

 secreted from the villi of the sensitive frog. 



" In a state of health of the foot, the se- 

 cretion of horn is unceasingly going on. 

 Disease or injury of the glandular parts may 

 diminish or altogether suspend the process ; 

 disease, under certain other forms, appears 

 also to have the effect of increasing it ; but 

 whether we have any artificial means of 

 effecting this, seems questionable. The 

 wall grows from above downwards. If a 

 mark be made in any part of the wall, it 

 will remain until it grows down and be- 

 comes cut off below, at the inferior border ; 

 and by observations made on the gradual 

 descent and disappearance of these marks, 

 calculations may be formed of the period 

 of time required for the renewal or restora- 

 tion of the wall. 



" PROPERTIES OF HORN. 



" Horn is a tough, flexible, elastic sub- 

 stance, consisting of tubular fibres, more or 

 less intimately connected together, taking 

 the direction from the surface of the body 

 on which it grows. Its property of tough- 

 ness or resistance much depends on its con- 

 dition in regard to moisture ; for if it is 

 exposed to a degree of heat sufficient to 

 abstract much of its natural juice or imbibed 

 moisture, it loses its flexibility and tough- 

 ness, and becomes brittle. On the other 

 hand, saturated with moisture, it is con- 

 verted into a soft and highly flexible sub- 

 stance, but at the same time becomes weak 

 and unresisting. This known effect aids us 

 to account for the flat-footedness of horses 

 reared in low, fenny, or marshy situations ; 

 the hoof being constantly in a state of 



saturation with moisture, the wall and sole 

 yield to the superincumbent burthen of the 

 body, and the latter grows flat (instead of 

 remaining concave or arched), and even in 

 some instances bulges. If oily or unctuous 

 applications have any effect in softening the 

 hoof, they appear to do so by filling the 

 crevices and interstices between the fibres 

 on the surface, and in this manner checking 

 or suppressing evaporation. Horn takes a 

 high and beautiful polish. Although much 

 inferior in transparency to tortoise-shell, it 

 may be worked up to bear so near a resem- 

 blance to it as to be often, in manufactures, 

 substituted for it, as in combs, etc. The 

 hoof admits of an elegant polish ; and in 

 that altered and improved state has been 

 manufactured into articles no less useful 

 than valuable and ornamental : * even the 

 hoofs of the living animal may, by being 

 kept clean, and when dry rubbed with lin- 

 seed oil, be numbered among the ornamen- 

 tal beauties Nature has bestowed upon 

 quadrupeds. 



" By chemical analysis horn has been 

 found to consist of membranous substance, 

 having the properties of coagulated albumen, 

 and of some gelatine. The horns of some 

 animals, the deer species, from containing 

 bone, become exceptions to this. Mr. 

 Hatchett burn" ^ve hundred grains of ox's 

 horn, and the residuum proved only one 

 and a half grain, not half of which was 

 phosphate of lime. 



" Shavings of hoof thrown into nitric 

 acid become soft, and speedily melt into a 

 yellow mass, which in about eight hours 

 disappear in complete solution. 



" The same thrown into sulphuric acid 

 turn black, in becoming soft, and require 

 thrice the time for their solution. Muriatic 

 acid also turns horn black, and corrodes 

 it, but has so little effect towards its solu- 

 tion, that after ten days a piece of hoof 

 soaked in it was found to have become only 

 more brittle or rotten. Common vinegar 

 will turn horn dark-colored, but does not 



* The Eclipse hoof, presented by his Majesty at Ascot 

 Races, as tlie reward of the best horse on the turf, forms 

 a notable illustration of this. 



