diseases of the digestive organs.

288 DISEASES OF CATTLE.of the operator, but not alone in the selecting and use of the appliances;for as much attention must be given to subsequent management. Thepatients are unreasonable, and a single awkward motion may undo thework of weeks so far as the union of the parts of the bone is concerned.It takes place after the same process and, if the conditions are favorable,with greater rapidity than in the human being. The injury thatcaused the fracture is almost sure to have extended to some of theadjacent tissues, and even though the fracture may be of the simplesttype there is almost sure to be considerable hemorrhage around theends of the broken bone. This, however, is unimportant if the skinremains intact, unless a very large vessel should be injured, or thefracture should open some of the important cavities of the body, inwhich case a fatal hemorrhage might result. If, on the other hand, thefracture be a compound one, the external opening furnishes a fertile fieldfor the lodgment of disease-producing germs. Unless great care is exercisedin such cases a suppurative process is likely to be establishedwhich will seriously interfere with if not entirely arrest the process ofunion between the bones; or it may become so serious as to endangerthe general health of the animal and even be attended with fatalresults. This last danger is greater where the injury has occurred tothe bones of the arm or thigh. In such cases, owing to the dense coveringof fascia which ensheathes the muscular covering, pus is likelyto be imprisoned, and burrowing downward saturate the whole structure,not only endangering the limb, but, being likely to be reabsorbed,may set up blood-poisoning and seriously interfere with the generalhealth of the patient, even to causing death. In order as far as possibleto prevent such an unfortunate complication the wound should becarefully cleansed with a mild solution of carbolic acid, then dustedover with iodoform before the bandages are applied, and cleansed anddressed daily in the same way. After dressing always cover withabsorbent cotton. In the early process of union an exudation of lymphtakes place, which is at first fluid,gradually becoming thicker andfirmer till it forms a callus in the shape of a ring or ferrule surroundingthe detached portions of the bone, known as the external orensheathing callus. It occasionally happens that this callus onlyformsat the ends of the bones, fillingthe spaces that exist between them,when it is known as the intermediate callus. The process of unionmay be divided into fivestages: In the firststage, including the firsteight days, the detached portions of the bone and the sharp projectionsthat are not sufficiently nourished are absorbed; the blood whichescaped into the surrounding tissues, the result of the injury, is graduallyabsorbed and the effused lymph which is ultimately to constitutethe temporary cartilage takes its place. In the second stage, from thetenth to the twentieth day, the tumor or callus is formed and fibrocartilageis developed inside and around the exposed end of the bone.In the third stage, extending from the twentieth to the fortieth or fif-