274 ENZOOTIC DISEASES. 



that veterinary surgeons have very rarely been consulted 

 regarding them. Shepherds have been trusted to. The 

 excessive mortality of one year has been set against the low 

 rate of loss of another, and landowners or their agents have 

 had to calculate that, in consequence of a particular disorder 

 prevailing on farms, the rental must be reduced so as to 

 enable the farmer to meet his losses. Thousands of acres of 

 land in different parts of the United Kingdom would be 

 worth much more than they are if enzootic disorders were 

 prevented. I believe that attention to this subject would 

 for many years to come add more to the resources of the 

 United Kingdom than the reclamation of land does. By all 

 means extend the available amount of country for the produc- 

 tion of food, but let us not forget to secure the full benefit of 

 what can be derived from the land on which our stock has 

 been fed for ages, which is deteriorated largely in value by 

 noxious properties that only require to be known in order to 

 be counteracted. These points will be best understood by 

 reference to the classifications of enzootic disorders which I 

 here append. 



Firstly, Enzootic disorders vary according to the geologi- 

 cal characters of districts and counties. Altitude exerts a 

 manifest influence on these diseases. The character of in- 

 digenous vegetation on mountains, hills, and lowlands ma- 

 terially influences the production of diseases in animals. 



Secondly, Enzootic disorders are due to excessive richness 

 and to excessive poverty of land. They are also due to 

 excessive moisture, or, on high and dry lands, to exposure. 

 They vary with different systems of culture: they are engen- 

 dered by forcing land to produce the largest and best crops, 

 or by impoverishing the soil in attempting to rear more than 

 it will bear. 



Thirdly, Enzootic disorders are induced by the manner in 



