DISEASES OF SHEEP. 271 



Many causes have been assigned for it, as the faciola hepaiica, or 

 fluke worm ; some particular plants eaten as food ; ground eating ; 

 snails and other ingesta : but as most of the supposed deleterious 

 herbs have been tried by way of experiment, and have failed to 

 produce the disease, so it is attributable to some other cause. — •' 

 Neither is there reason to suppose that the fluke worm occasions 

 it, since we know the biliary vessels of other animals, as horses, 

 asses, rats, &c. often have them ; and above all, because that they 

 are not always present in the rotted subject. From long expe-. 

 rience and the almost invariable effect produced by a humid state 

 of atmosphere, soil, and product, we are warranted in concluding 

 these are the actual and immediate agents ; perhaps the saturated 

 food itself is sufficient to do it. The morning dew has been sup- 

 posed equal to it. Bakewell, v;^hen his sheep were past service, 

 used to rot them purposely, that they might not pass into other 

 hands. This he always readily did by overflowing his pasturages. 

 But great differences of opinion exist as to the quantity, form, and 

 varieties of moisture productive of this fatal disease. It is said 

 that land on which water flows, but does not stagnate, will not rot 

 however moist ; but this is contradicted by the experience of Bake- 

 well, who used merely to flood his lands a few times only to rot 

 his sheep. It is also said that they are safe from rot on Irish bogs, 

 salt marshes, and spring flooded meadows, which experience seems 

 to verify. It is also said that the very hay made from unsound 

 land will rot ; but this wants confirmation. When salt marshes 

 are found injurious it is only in such years when the rain has satu- 

 rated, or rather super-saturated such marshes. That putrid exha- 

 lations unaccompanied with moisture can occasion rot, wants con- 

 firmation also ; for these commonly go together, and it is difficult 

 to separate their effects. It is not perhaps the actual quantity of 

 water immediately received by land, but the capacity of that land 

 to retain the moisture, which makes it particularly of a rotting 

 quality. 



228. The signs of rottenness are sufficiently familiar to persons 

 about sheep. They first lose flesh, and what remains is flabby 

 and pale ; they lose also their vivacity. The naked parts as the 

 lips, tongue. Sec. look livid, and are alternately hot and cold in the 

 advanced stages. The eyes look sad and glassy, the breath is 

 foetid, the urine small in quantity and high coloured ; and the 

 bowels are at one time costive and at another affected with a black 

 purging. The pelt will come off on the slightest pull in almost all 

 cases. The disease has different degrees of rapidity, but is always 

 fatal at last This difference in degree occasions some rotted 

 24* 



