46 DISEASES OF SHEEP. 



sequences, and in such periods certain unaccountable influ- 

 ences, such as an unknown state or composition of the 

 atmospheric air, may exist. Sheep pox is of a very con- 

 tagious character; of this there can be no doubt at all. 

 All parts of the diseased animal contain contagious matter, 

 especially the lymph, the blood, the discharges of the 

 mouth and nose, the dung, the urine and the exhalation 

 of the skin and lungs. Contagion may result either from 

 immediate contact with said infected parts, or from the 

 transfer of the poisonous matter by intermediate means or 

 poisonous air. Contagion is generally introduced into a 

 herd by single animals, which are or have been afflicted 

 with pox, by means of the wool or skin of such animals, 

 or when healthy animals feed upon pasture where diseased 

 sheep have been roaming. The disease may also be trans- 

 ferred by contact with infected clothing of men, especially 

 fur, and even by dogs and poultry. The contagious matter 

 of the pox, being of a volatile nature, can consequently 

 become diffused by air. It is not known to what extent 

 such a diffusion may effect contagion ; it is, however, pro- 

 bable that within several hundred years such a diffusion 

 may prove fatal. It is extremely seldom that pox breaks 

 out in a single herd without any previous appearance of 

 said disease in some other part of the neighborhood. The 

 manner in which such infection from one remote locality to 

 the other has been effected has been never sufficiently ex- 

 plained, except in a very few cases. Such sudden and un- 

 explained attacks only prove the intensity and subtilty of 

 the contagious matter of sheep pox. Such matter pre- 

 serves its nature and effects for a long time, even in the 

 dry state, and long after the disease itself has ceased to 

 exist. In the beginning only a few animals of a certain 

 herd are affected by pox (probably from immediate infec- 

 tion). It never happens that the entire herd, or the larger 



