32 DISEASES OF SHEEP. 



atmosphere is overloaded with electrical fluid before a 

 thunder-storm. 2. A large number of cases occur upon 

 pastures of a very abundant but loosely-constructed bottom, 

 which is subject to sudden change from the influences of 

 dryness or rain, by which influences the pasture may be- 

 come drained or inundated in a very short time. 3. In 

 deep valleys containing rivers and rivulets, where there is 

 little draft of air, and the atmosphere is filled with ascend- 

 ing vapors, where the solar rays, after gliding down the 

 face of the mountains, concentrate upon the bottom of 

 the valleys, and no ventilation by drafts of air or wind 

 taking place, the animal must suflTer from such permanent 

 efiects. 4. Blood disease often occurs upon lands or estates 

 with differently situated soil, where the vegetation is easily 

 destroyed by heat and dryness upon the higher situated 

 part, at the same time that abundance prevails in the val- 

 ley, or a sudden change is produced after a rain. 5. Blood 

 disease very often and generally occurs upon lands where 

 the vegetation is subject to mildew or blight. 6. The dis- 

 ease also appears upon lands of a very loose and sandy 

 bottom, which, together with parts of its vegetation, may 

 be washed away or spoiled with ra,in, where there are no 

 drains to prevent the formation of cavities in'which vegeta- 

 tion may to some extent remain, and other parts exposed 

 to rot or dryness. 7. It often happens amongst sheep feed- 

 ing upon pastures which are from time to time subject to 

 inundations. 8. It often happens amongst sheep which 

 suddenly change from leanness to fattening. 9. Another 

 cause of said disease consists in over-feeding with very rich 

 and flatulent food amongst herds which are not accustomed 

 to such feeding. 10. When over-feeding with grain and 

 clover hay had taken place, the disease was generally ob- 

 served to follow, even during winter. 11. The same thing 

 happened when the stables were kept too warm. 12. The 



