Snapper was one of the first to demonstrate the relationship between generalized fibrocystic disease of the bones (often called von Recklinghausen's disease) and parathyroid adenoma. For more than twenty years since this initial contribution to the metabolic diseases of the human skeleton, Snapper has constantly brought the light of truth to bear on many other diseases which affect in a general way the human skeleton; he has helped clarify understanding of their causes, and, when possible, the means of controlling them.
In the first edition all the commoner bone diseases were presented, with emphasis on the systemic manifestations. In the second edition, the chapter on hyperparathyroidism is subdivided into four parts. New chapters on osteoporosis and osteoporosis circumscripta cranii, osteitis fibrosa disseminata, leontiasis ossea, neurofibromatosis of the bones, lymphosarcoma, Hodgkin's disease and hemolytic anemias are added. Other chapters are enlarged or subdivided to clarify the differential picture between conditions which