CHAPTER IIT.
DISEASES OF PERIOSTEUM.
IXFLAMMATION OF PERIOSTEUM.
Sypuitis, rheumatism, and serofula are well-recognized eauses of inflammation of periosteum; it also occurs, se- eondarily, from inflammation in the medullary membrane, or walls of the bone. In systems debilitated by mercury, and thus rendered particularly suseeptible of the influenees of eold and moisture, inflammation of periosteum upon one, and often on several bones, is of commen cecurrenec ; these belong to the class of rheumatie eases, and it is pro- bably because the surfaces of bones superficially situated are most exposed to external influences, that these are the usual seat of periostitis. By the same consideration it may be explained why periostitis upon the posterior surface of the tibia is rare; and fortunately it is so, for the serous or purulent fluid, here effused beneath the perios- teum, would be seareely within reach of relief by surgieal interference.
Among the examples of syphilitie periostitis are in- stances of its ocenrrenee from the action of the gonorrhesal virus alone, and independently of rheumatism. The fol- lowing is a well-marked case of this kind. A gentleman had, in the course of ten ycars, three attaeks of gonorrhaca, �
