DISEASES OF SHEEP. 57 



several cases proved inefficient, and there having been a 

 difference of opinion in regard to the efficiency of " precau- 

 tionary vaccination," the establishment of certain so-called 

 " vaccine dep6ts" was suggested, and such institutions have 

 been dulyiestablished, in connection with large estates, in 

 some parts of Austria. The proper management of such 

 vaccine dep6ts, which involved considerable expense and 

 great care, consisted in the separation of small flocks, keep- 

 ing the same at some remote and isolated spot from the 

 main flock, and vaccinating only about ten animals of such 

 separated flock ; from these a single animal possessing the 

 most favorable qualities was selected from which to obtain 

 the vaceine-matter, by which another lot of ten sheep were 

 vaccinated, and so on until the arrival of the proper time 

 for the vaccination of the entire grown-up stock. Such a 

 mode of operation offers, of course, the surest means to 

 have good vaccine-matter of sufficient quantity on hand 

 when required. But this mode of obtaining and preserving 

 good vaccine-matter was not the only object or purpose of 

 such institutions ; it was also believed that such repeated 

 transplantation or propagation of lymph through a large 

 number of healthy sheep would at last produce a very mild 

 and entirely innoxious form of pox, without lessening the 

 protective virtues of the vaccine-matter of the same ; thereby 

 also avoiding a general infection or death from such disease. 

 Such a supposed mitigation was called "Culture or mitiga- 

 tion of vaccine-matter," and such vaccine-matter was said to 

 possess the following advantages over vaccine-matter ob- 

 tained from natural pox, namely : 1. Cultivated vaccine- 

 matter was said to be of the same preventive power against 

 infection from natural pox as matter taken from the latter. 

 2. It was believed that cultivated vaccine-matter is ren- 

 dered milder by each further transplantation, forming only 

 a single pox upon the vaccinated spot, and avoiding a 



