272 DISEASES OF CATTLE. 



uient. The patients are unreasonable, and a single awkward motion 

 may undo the work of weeks so far as the union of the parts of the bone 

 is concerned. Union takes place after the same process and, if the 

 conditions are favorable, with greater rapidity than in the human 

 being. The injury that caused the fracture is almost sure to have 

 extended to some of the adjacent tissues, and, even though the frac- 

 ture may be of the simplest type, there is almost sure to be consider- 

 able hemorrhage around the ends of the broken bone. This, however, 

 is unimportant if the skin remains intact, unless a very larg8 vessel 

 should be injured, or the fracture should open some of the important 

 cavities of the body, in which case a fatal hemorrhage might result. If, 

 on the other hand, the fracture be a compound one, the external open- 

 ing furnishes a fertile field for the lodgment of disease-producing germs. 

 Unless great care is exercised in such cases a suppurative process 

 is likely to be established which will seriously interfere with, if not 

 entirely arrest, the process of union between the bones; or it may 

 become so serious as to endanger the general health of the animal 

 and even be attended with fatal results. This last danger is greater 

 where the injury has occurred to the bones of the arm or thigh. In 

 such cases, owing to the dense covering of fascia which ensheathes 

 the muscular covering, pus is likely to be imprisoned, and, burrowing 

 downward, saturate the whole structure, not only endangering the 

 limb, but, by absorption, may set up blood poisoning and seriously 

 interfere with the general health of the patient, even to causing death. 

 In order so far as possible to prevent such an unfortunate complica- 

 tion, the wound should be carefully cleansed with a mild solution of 

 carbolic acid, then dusted over with iodoform before the bandages 

 are applied, and cleansed and dressed daily in the same way. After 

 dressing always cover with absorbent cotton. In the early process of 

 union an exudation of lymph takes place, which is at first fluid, grad- 

 ually becoming thicker and firmer till it forms a callus in the shape 

 of a ring or ferrule surrounding the detached portions of the bone, 

 known as the external or ensheathing callus. It occasionally happens 

 that this callus only forms at the ends of the bones, filling the spaces 

 that exist between them, when it is known as the intermediate callus. 

 The process of union may be divided into five stages. In the first 

 stage, including the first eight days, the detached portions of the bone 

 and the sharp projections that are not sufficiently nourished are 

 absorbed; the blood which escaped into the surrounding tissues, the 

 result of the injury, is gradually absorbed, and the effused lymph, 

 which is ultimately to constitute the temporary cartilage, takes its 

 place. In the second stage, from the tenth to the twentieth day, the 

 tumor or callus is formed and fibrocartilage is developed inside and 

 around the exposed end of the bone. In the third stage, extending 

 from the twentieth to the fortieth or fiftieth day, according to the age 

 and strength of the animal, the fibrocartilaginous structure under- 



