PRINCIPLES OF VETERINARY SURGERY 601 



that the proportion of phosphates increased as they entered 

 lands where the disease did not exist at all. 



The constitution of the forage depends entirely upon 

 that of the land. Analogous statements on the subject, 

 with analyses to support them, have been made by the 

 Veterinary Society of L'Aube in 1893. This theory is, 

 however, only that of inanition of the German authors, 

 based chiefly on the experiments of Rolofif and Voit, who 

 were able to reproduce osseous cachexia experimentally by 

 diminishing the proportions of lime salts in the aliment. 

 The part played by alimentation in the development of the 

 disease has also been proven by Germain in Cochin China 

 and by Theiler of the Cape country. The experiments of 

 Rolofif and Voit are, however, subject to criticism, because 

 they used only young animals for their experimental sub- 

 jects. 



Other opinions confirm the theory of alimentation. Zun- 

 del attributes the disease to soils abounding with silicates, 

 which as a consequence, do not retain water, and Hertwig, 

 on the contrary, claimed that clay sub-soils play an import- 

 ant part. It is, however, important to note that the disease 

 may occur where the land is rich in calcium carbonate and 

 poor in phosphoric acid. Yagow has attributed the disease 

 to a dearth of calcareous salts in the water supply, and Ros- 

 signol, who observed it in animals fed on the by-products of 

 distilleries and sugar-refineries, blamed the poverty of these 

 feeds in phosphates. 



All of these influences are indirectly associated with ali- 

 mentation, as the character of the soil affects the nutritive 

 value of its flora. The influence of drouth on vegetation 

 has often been held responsible for the disease, as it leads to 

 the growth of feeds having a dearth of nutritive elements, 

 especially of salts, which, lacking water as a conveyance, 

 remain incorporated in the soil. This theory is held by 



