“Osseous cachexia” is a general disease which develops slowly and progressively, producing its most marked effects on the bony tissues. It has received a great many different names, such as osteoporosis, osteoclastia, osteomalacia, fragilitas ossium, enzootic ostitis, bone softening, etc., but none of these appears so appropriate as the term osseous cachexia, suggested by Cantiget. All the above-mentioned names are applicable to some phase of the disease, but none to the disease in its complete development. Thus the name “osteoporosis,” accepted by German authors, is quite applicable to the phase of rarefying ostitis seen at the commencement, but this condition occurs in other diseases. The expressions “osteoclastia” and “fragilitas ossium” suggest the fragility of the bones and the commonness of fracture. The term “osteomalacia” is warranted during the period of bone softening. The term “gout,” though in practice confusing, has been held to be justified by the frequent appearance of synovitis and arthritis; while that of “enzootic ostitis” indicates the appearance of the disease in all the stables in one district, without however pointing to its nature. It is possible that under certain circumstances the train of symptoms might be incomplete, and then the terms above indicated would be quite inappropriate. “Osseous cachexia,” on the other hand, is very comprehensive, and appears to cover the entire development of the disease, for which reason it here receives preference. Law defines the disease as “a softening and fragility of the bones of adult animals, in connection with solution and removal of the earthy salts.” He describes it as an enzootic disease of mature animals—mainly cows—in which the decalcifying process proceeds most actively in the walls of the Haversian canals and cancelli of the affected bones. In consequence of the removal of the earthy salts the bones become soft and more or less fragile. The disease has been observed in England, Scotland, United States, France, Belgium, and Jutland, and generally in districts with low-lying damp pastures. It attacks cows which are heavy milkers. Susceptibility appears to increase with advancing age.