There are different ways of dealing with a bone cavity. It may be packed with gauze (impregnated with "bipp" or with iodoform), which is changed at intervals until healing takes place from the bottom; it may be filled with a flap of bone and periosteum raised from the vicinity, or with bone grafts; or the wall of bone on one side of the cavity may be chiselled through at its base, so that it can be brought into contact with the opposite wall. The method of filling bone cavities devised by Mosetig-Moorhof, consists in disinfecting and drying the cavity by a current of hot air, and filling it with a mixture of powdered iodoform (60 parts) and oil of sesame and spermaceti (each 40 parts), which is fluid at a temperature of 112°

The bone also begins to die when the skin and periosteum is stripped off, and the hormone from this also ceases to be produced. The annual shedding and recrescence of the antler, however, is only to be understood in connexion with the effect of the testicular hormone.

There was no wound visible, but it was soon evident that the periosteum had become inflamed from the contusion. As the pain increased more and more with the use of the thumb, I was ordered to do no writing until my hand was quite healed.

At the Emergency Hospital in Washington, D.C., there was received a negress with at least six gaping wounds of the head, in some cases denuding the periosteum and cutting the cranium. During a debauch the night before she had been engaged in a quarrel with a negro with whom she lived, and was struck by him several times on the head with an axe.

#Regeneration of Bone.# When bone has been lost or destroyed as a result of injury or disease, it is capable of being reproduced, the extent to which regeneration takes place varying under different conditions. The chief part in the regeneration of bone is played by the osteoblasts in the adjacent marrow and in the deeper layer of the periosteum.

The affected bones lose their rigidity, so that they are bent under the weight of the body, by the traction of muscles, and by other mechanical forces. The periosteum is thick and vascular, and when detached carries with it plates and spicules of soft porous bone.

The term caries is employed to indicate any diseased process associated with crumbling away of the trabecular framework of a bone. It may be considered as the equivalent of ulceration or molecular destruction in the soft parts. The carious process is preceded by the formation of granulation tissue in the marrow or periosteum, which eats away and replaces the bone in contact with it.

The portion of the diaphysis which has sustained the action of the concentrated toxins has its vitality further impaired as a result of the stripping of the periosteum and thrombosis of the blood vessels of the marrow, so that necrosis of bone is one of the most striking results of the disease, and as this takes place rapidly, that is, in a day or two, the term acute necrosis, formerly applied to the disease, was amply justified.

Crepitation or a grinding, rubbing sound due to the movement of the ends of the broken bones on one another occurs when the part is moved or manipulated with the hands. Pain, swelling and injury to the skin are other local symptoms. The new tissue or bone callus is formed by the bone-forming cells in the deeper layer of the periosteum and bone-marrow. The prognosis is unfavorable.

Chondroma, or enchondroma, is a cartilaginous tumor occurring principally where cartilage is normally found, but sometimes in regions containing no cartilage. Enchondroma may be composed of osteoid tissue, such as is found in the ossifying callous between the bone and the periosteum, and, according to Virchow, then takes the name of osteochondroma.