Before considering the following cases of calcareous degeneration found in the thoracic region, a brief review of the subject seems advisable. The chemical, physical and clinical evidences of pathologic calcifications have been noted from time to time for many years; interesting cases have been reported in the literature and important treatises written regarding cause and effect.
Aristotle and Galien1 mentioned cases of "stone in the lung" in their records. Sommering2 in 1769 wrote of a case of pulmonary calcification which he considered as a secondary manifestation (metastasis). In 1824, Rullier3 reported a case of primary calcification of a right upper lung in which a great number of calcified fragments were found. Furhmann4 thought that the deposition of calcium salts might follow any chronic irritation of the body tissues, and that this explanation accounted for "exercise bone" (calcium formation in deltoid muscle) and "the riders' bones," which proved to be calcium