Wegner has furnished definite proof that phosphorus stimulates the growth of true bone, for, after giving minute doses continuously to animals, he found the epiphyseal cartilages ossify more quickly and more completely than usual, and the cancellous and compact bone become more dense, even to the extent of obliterating the medullary canal (Virchow's Archiv, June 22, 1872). Exostoses commonly form in cattle feeding near the bone-works at Swansea, and have been plausibly traced to phosphorus fumes in the surrounding atmosphere (Stanley on Bones: Medical Times, 1854), and although we find clinically that inflammation and necrosis follow the direct local irritation of strong phosphorus vapor, yet even in such cases exostoses commonly form in another part of the same bone.