12 



The Rot in Sheep. 



well has attended to it more than most men in England. He is 

 extremely clear, from long attention, that this disorder is owing 

 solely to floods — never to land being wet only from rains which 

 do not flow, nor from springs that rise. He conjectures that the 

 young grass, which springs in consequence of a flood, is of so 

 flashy a nature that it occasions this common complaint. But, 

 whether this idea is just or not, still he is clear in his facts, that 

 floods (in whatever manner they act) are the cause. 



" Perhaps the most curious experiment ever made in the rot 

 of sheep is what he has frequently practised. When particular 

 parcels of his best-bred sheep are past service, he fats them for 

 the butcher ; and, to be sure that they shall be killed, and not go 

 into other hands, he rots them before he sells, which, from long 

 experience, he can do at pleasure. It is only to flow a pasture 

 or meadow in summer, and it invariably rots all the sheep that 

 feed on it the following autumn. After the middle of May, water 

 flowing over land is certain to cause rot, whatever be the soil. 



" He has acted thus with several of his fields, which, without 

 that management, would never affect a sheep in the least ; the 

 water may flow with impunity all winter, and even to the end of 

 April, but after that the above effect is sure to take place. Springs 

 he asserts to be no cause of rotting, nor yet the grass which rises 

 in consequence, unless theyfloiv. Nor is it ever owing to the 

 ground being very wet from heavy rains, unless the water flows. 

 This theory of the rot " (adds Young), " upon the whole, appears 

 satisfactory ; and that part of it which is the certain result of 

 experience, cannot be doubted." 



The next author in the order of date (1804) whose opinions 

 we shall notice with reference to the cause of rot is Dr. Harrison. 

 We have already had occasion to quote from his writings 

 respecting an outbreak of this disease in 1792. 



Under the head of Causes of Hot, he says, " the disorder has 

 been imputed — 



" 1st. To a vitiated dew. 



" 2ndly. To a graft, which adheres to the grass after wet 

 weather in the overflowing of running water. 



" 3rdly. To the luxuriant and quick growth of plants in hot, 

 moist seasons. 



" 4thly. To grazing upon certain herbs ; of which the Butter- 

 wort (Pinguicula vulgaris), White-rot (Hydrocotyle vul- 

 garis), Round-leaved Sundew {Drosera rotundifolia), and 

 the Long-leaved Sundew (Drosera longifolia) have been 

 chiefly suspected. 



" 5thly. To Fasiolye hepatica? — flukes, or their ova — being 

 introduced into the stomachs of animals by feeding on 

 swampy and low grounds in moist weather. 



