408 DISEASES OF THE HOESE. 



of gum ammoniac. The number of clasps to be used is to be deter- 

 mined by the length of the crack, the amount of motion to be arrested, 

 etc. Generally the clasps are from one-half to three-quarters of an 

 inch apart. The clasps answer equally as well in quarter-crack if the 

 wall is sufficiently thick and not too dry and brittle to withstand the 

 strain. 



In the absence of these instruments and clasps a hole may be drilled 

 through the horn across the fissure and the crack closed with a thin 

 nail made of tough iron, neatly clinched at both ends. A plate of 

 steel or brass is sometimes fitted to the parts and fastened on with 

 short screws; while this appliance may prevent much gaping of the 

 fissure, it does not entirely arrest motion of the edges, for the simple 

 reason that the plate and screw can not be rendered immobile. 



If, for any reason, the above measures fail or can not be used, 

 recourse must be had to an operation. The horn is softened by the 

 use of warm baths and poultices, the patient cast, and the walls of the 

 fissure entirely removed with the knife. The horn removed is in the 

 shape of the letter V with the base at the coronet. Care must be taken 

 not to injure the coronary band and the laminae. The wound is to be 

 treated with mild stimulant dressings, such as creolin, a weak solu- 

 tion of carbolic acid, tincture of aloes, etc., oakum balls, and a roller 

 bandage. After a few days the wound will be covered with a new, 

 white horn, and the oakum and bandages only will be needed. As the 

 new quarter grows out the lameness disappears, and the patient may 

 be shod with a bar shoe and returned to work. 



In all cases of sand-crack the growth of horn should be stimulated 

 by cauterizing the coronary band or by the use of blisters. In simple 

 quarter-crack recovery will often take place if the coronet is blistered, 

 the foot shod with a " tip," and the patient turned to pasture. 



The shoe in toe-crack should have a clip on each side of the fissure 

 and should be thicker at the toe than at the heels. The foot should be 

 lowered at the heels by paring, and spared at the toe, except directly 

 under the fissure, where it is to be pared away until it sets free from 

 the shoe. 



When any of the complications referred to above arise, special 

 measures must be resorted to. For the proper treatment of gangrene 

 of the lateral cartilage and extensor tendon and caries of the coffin 

 bone reference may be had to the articles on quittors. If the horny 

 tumor, known as keraphyllocele, should develop, it is to be removed 

 by the use of the knife. Since this tumor develops on the inside of 

 the horny box and may involve other important organs of the foot in 

 disease, its removal should only be undertaken by a skillful surgeon. 



