74 



BOARD OF AGRICULTURE. 



years. This system has for its basis the causes of disease, 

 and, by it, all diseases are divided into five classes : 1. The 

 Zymotic ; 2. The Constitutional ; 3. The Local ; 4. The 

 Developmental ; 5. The Violent. These five classes are di- 

 vided into twenty-one orders, and these twenty-one orders 

 into an undetermined number of so-called diseases. 



With this formidable array of diseases assailing us from 

 before and behind, and at either side, above and all around 



