2-2 SMALL- POX IN SHKKP. 



siicli inquiries as would enable us to trace these sheep, 

 with a view to satisfy oui'selves with reference to the 

 orii;in of the malady. 



Difficulties generally attend investigations of this 

 kind, and we are often unable to obtain sufficient in- 

 formation respecting the time of the introduction of a 

 contagious disease; and the uncertainty is increased 

 from the circumstance that very different laws are ob- 

 served to govern the spread of epizootics, many of which 

 owe both their origin and their extension to a vitiated 

 condition of the air, which, being wafted far and wide, 

 canies destruction in its course ; as we observed in the 

 first Chapter. Such maladies as these break out in 

 several places about the same time, and here and there 

 animals fall victims to their devastating effects : in fact, 

 no legislative enactments can prevent epidemics of this 

 class entering a country, whether insular or not. Means, 

 however, can easily be adopted to stop the course of 

 contadon, and also of infection : the latter is well known 

 to have its limits in many cases, and, as elsewhere 

 ex})lained, unless animals come within its sphere, or are 

 placed near the infected, their health does not suffer. 



All diseases possessing characters like those above 

 named are not, however, of foreign origin ; and it is a 

 subject of regret that, \^dthin our " sea-girt isle," causes 

 which might be modified, if not prevented, are far too 

 frequently allowed to exert their injurious effects on 

 our flocks and herds, and to give rise to endemic affec- 

 tions. Ovine pox belongs to foreign countries : the 

 question of its infectious nature \nll be hereafter dis- 

 cussed, but its contagiousness is fully established by 

 many proofs daily occurring. 



Every encouragement being given to, and great faci- 



