310 



Diseases of Sheep. 



become luxuriant and rank by excessive rain and extreme solar 

 heat combined, rots av/ay suddenly and exhales a miasma. The 

 form in which disease at this period attacks the human frame is 

 commonly called dysentery and hepatic affection. I have under- 

 stood, from some who have long resided at Freetown, that the 

 stench of putrid vegetable matter, accumulated even in the streets 

 during the rainy season and immediately after its termination, is 

 offensive to the highest degree. May we not infer that the taint 

 of rot proceeds from the same cause ? for though the miasma, in 

 the pasturage I have alluded to, may not be produced in sufficient 

 quantity to affect the human subject, standing upright at a distance 

 from the effluvia, it may be sufficient to affect the animal that in 

 feeding has his nose in constant and close contiguity to the soil. If 

 we are justified in this reasoning, the inferences to which it leads 

 are most important. I do not mean to claim the merit of origin- 

 ality in this view of the subject. It has long been a prevailing 

 opinion that the rot originates in marshy exhalations, but it is de- 

 sirable to arrive at some conclusion which is at least founded on 

 plausibility, in considering the variety of causes to which rot has 

 been ascribed ; and of all the many speculations to which the in- 

 genuity of theorists, or the more homely ideas of practical men 

 have given rise, I think that the theory on which I have dwelt is 

 most consistent with the experience of the farmer. I will, how- 

 ever, admit that there are many sensible men who consider that 

 the disorder is propagated from the qualities of their food, and 

 not from exhalation, as it has been remarked that close feeding 

 is almost essential to the contagion. In the parish of Seaton, in 

 Devonshire, all the sheep that were depastured on the marshes 

 one year were attacked with rot, and died, only excepting four ; 

 on examining these four, it was found that they v/ere hog-jawed, 

 and, from the under jaw being very much shorter than the upper, 

 they could not bite near the ground.* 



* It appears in this part of the Essay that many different opinions have 

 arisen respecting the cause of rot in sheep ; I therefore heg to state my 

 opinion and experience on the subject in as short and explanatory a way as 

 possible. I would beg to say that I do not think sheep become rotted from 

 every kind of wet land whether drained or not, but from a particular cha- 

 racter of soil and subsoil : soil of this description is inclined to bog or quag- 

 mire, although it may not have that appearance on the surface of the land, 

 but may lie 8 or even 12 feet deep. Between this subterraneous bog and 

 the surface there is generally a hard stratum of blue clay or sand, tainted 

 with the bog-water, lying underneath at that depth ; and this infectious 

 water is brought up from the bog to the surface of the earth by means of 

 small pipes which are always found to form the communication between 

 them, and called by experienced land-drainers bog-pipes. In consequence 

 of this infectious water thus arising to the surface, a plant is produced — 

 not of the grass-tribe, but called by some old experienced shepherds the 



