The Rot in Sheep. 



13 



" fithly. It is ascribed by Daubenton to poor diet and drinking 



too much water. 

 " 7thly. It seems to be occasioned by poisonous effluvia, which 



under certain circumstances are emitted from marshy soils." 



Dr. Harrison advances arguments against all these suppo- 

 sitions, with a view to refute them, with the exception of the last, 

 which he endeavours to prove is the true and only cause. Speak- 

 ing of the influence of the sun's rays on swampy ground, he 

 remarks : " Evaporation is copiously performed, and probably 

 some of the water is decomposed, so as to generate in combina- 

 tion with other substances the poisonous effluvia, called miasmata 

 pallidum, which occasion the rot in animals." In another place 

 he remarks : " For my own part, I have declared for several years 

 in various companies that marsh miasmata are the cause of both 

 agues and rot." 



Hereafter we shall offer some remarks on this opinion of 

 Harrison's, especially as we find it adopted by some modern 

 authorities on diseases of sheep. In the meantime, we con- 

 tinue our extracts from other writers. 



Hogg — The Ettrick Shepherd — observes in The Shepherd's 

 Guide, 1807, that " it is a curious circumstance that of all other 

 diseases of sheep, the greatest variety of opinions prevail with 

 respect to the real cause of this, and amongst such a number 

 it may reasonably be suspected that it is very difficult to alight 

 upon the right one ; but i have stuck to a theory laid down by a 

 few of the most sensible men on the Duke of Buccleuch's estates, 

 who have had abundance of experience that way, and which 

 seems to account at once for all the different opinions. Yea, 

 I hope to make it appear that all the various causes assigned 

 for the rot only serve more fully to prove this the real and 

 ultimate one. But, not to keep the reader in suspense, I hold 

 it as an incontrovertible fact that a sudden fall in condition is the 

 sole cause of rot." 



Sir George Steuart Mackenzie in his Treatise on the Diseases 

 and Management of Sheep, 1809, combats the Ettrick Shepherd's 

 opinion, and asserts that " all the species of rot may be reduced 

 to one, and all the symptoms maybe referred to unirh ole some food '." 

 He says that " Mr. James Hogg and others assert that the rot is 

 caused by ' a sudden fall in condition.' As these gentlemen 

 do not mention what in their opinion occasions the (all, wo may 

 safely presume that it is not meant to ascribe it to any other 

 cause than hunger. But hunger is not properly a disease, and 

 its effects on the animal economy arc very different from rot, 

 whether the privation of food be sudden or gradual. Besides, 

 we often hear of sheep having been buried in snow for weeks 

 together, a situation in which they must be subjected to a fall 



