The Rot ill Sheep. 
125 
remedies rests on our b(>ing enabled to fix the time of the 
commencement of the disease. It is the circumstance of sheep 
fallinj^ away in flesh, and exhibiting tlie general symptoms of rot 
in the autumn, that has too often led to incorrect conclusions as to 
the time of the origin of the malady. Efi'ects have been mistaken 
for causes. Men have not generally known that from three to 
four months are frequently needed for flukes in the liver to pro- 
duce their debilitating effects on the organism of the sheep. 
Elsewhere we have explained the reasons why an elevated tempe- 
rature, combined with excess of rain-fall, is dangerous, and need 
not repeat the argument. We may, however, add that with 
the end of October ..all danger, as a rule, has passed awav ; the 
approach of cold weather, and especially the occurrence of frosts, 
speedily removing the cause of the mischief. The natural history 
of the liver-fluke also satisfactorily explains this. If it be true that 
practical men hold that the autumn is the most dangerous period 
of the year to sheep, it is equally true that they agree that a 
frost at once puts a stop to the reception of the rot. Fairburn, 
in combating Hogg's opinion of the cause of the disease, remarks, 
" I have lost from time to time a great number of hoggs by 
poverty, and I could certainly trace their death to ' want of meat 
and shelter ; ' but there were none of those diagnostic symptoms 
apparent which indicate the complaint called rot. Cold and 
frosts are always severe on hunger-stricken hoggs ; but I have 
iinifonnh/ found that frost pj-evcntcd the rot, and that if the disease 
had not been taken previous to the arrival of frost, it never fol- 
lowed that kind of iceatherT 
Symptoms of Rot. 
As every disease is accompanied with a train of phenomena 
usually designated symptoms, it becomes necessary that these 
should be carefully investigated, so that the nature of each sepa- 
rate affection may be fully understood. The importance of this 
procedure is further shown by the circumstance that many 
symptoms are common to several diseases ; while others, on the 
contrary, belong only to particular affections, and hence afford 
the pathologist a ready means of forming a correct diagnosis. 
Sthenic diseases as a rule, and especially those centered in the 
more important organs of the body, are accompanied with such 
well-marked peculiarities, that the practitioner rarely fails in re- 
cognising either their nature or seat. Asthenic maladies, on the 
contrary, are often attended with such general or ambiguous 
symptoms, that even the most experienced pathologist may, at the 
outset, fail to fix their site or determine their true character. 
Affections, however, of internal organs, which commence with 
