T64 FRANCIS H. McCRUDDEN 



lungs, pleura, eye, stomach, liver and lymph nodes is fairly common. In 

 twenty-nine cases of metastatic bone formation reported in the litera- 

 ture, some extensive destructive disease of bone was demonstrated in all 

 but four (McCrudden(/)) ; and it is very probable that a systematic 

 search such as Hanau made for evidences -of osteomalacia in the bones 

 of pregnant women would disclose evidence of mild grades of osteomalacia 

 in all these cases. 



A diet deficient in calcium can give rise to osteomalacia. The first 

 experiments in this direction were undertaken by Chossat(a) in 1842. 

 Chossat fed pigeons a diet, poor in calcium salts wheat, well extracted 

 with water. After some months the bones of the pigeons became fragile, 

 and at autopsy the normal bone was found to be replaced in part by 

 a kind of soft cartilaginous material. On the same diet plus calcium 

 carbonate the pigeons remained well. Nearly twenty years later, Edwards 

 who repeated these experiments, obtained the same results. 



A diet deficient in calcium is especially effective in causing bone 

 diseases when the need of the body for calcium is great during the 

 growing period and during pregnancy. In 1875, Roloff(a) observed 

 that young dogs and swine kept on a diet deficient in calcium salts 

 developed rickets. \ r oit developed rickets in a growing dog by adminis- 

 tering a calcium-poor diet ; a control animal receiving the same diet 

 Avith the addition of bone ash did not develop rickets (Voit(a)). Stoetz- 

 ner and Salge carried out substantially the same experiment as Voit 

 with the same result. In 1879 Roloff(6) kept a sheep during the 

 whole period of pregnancy and lactation on food from which the calcium 

 salts had been dissolved out with hydrochloric acid. The animal de- 

 veloped severe osteomalacia, the diagnosis being confirmed at autopsy. 

 In the same way Dibbelt, and also Stilling and Mering produced 

 osteomalacia in pregnant dogs. More recently Weiser(fc) selected 

 six young pigs of the same age and race, and to three of them ad- 

 ministered a diet poor in calcium while to the other three he admin- 

 istered a diet containing an abundance of calcium. Bone analysis 

 showed a much lower calcium content in the set whose diet was deficient 

 in calcium. 



A deficiency of calcium in the diet is often responsible for spontane- 

 ous osteomalacia in animals. This disease, referred to as malnutrition 

 of the bones by veterinarians, occurs in oxen, cows, horses, sheep, goats, 

 swine, dogs, rabbits and rats. It is especially common in parts of France, 

 where it is called cachexie osseuse or maladie des pattes; in swine it is 

 called maladie de gouttes, and in horses maladie du son (Badolle). The 

 disease occurs also in the United States, especially in southern Alabama, in 

 western Washington, and in parts of Mississippi and Florida. In the sec- 

 tions of Alabama and Washington where the disease is prevalent the 

 soil is very poor in lime (Forbes, Halberson and Morgan). 



