432. History of Animal Plagues. 



matter to the proprietor whether he wait until all are attacked 

 with the disease or are killed at once. This urgent measure is 

 of adv^antage to him^ because he is then paid the full value ; 

 whereas he only gets a third when the malady has developed 

 itself. This severe law^ however^ requires great care in its exe- 

 cution, if a government has not the courage to carry it out 

 everywhere at the same time. If not, then it becomes a vexatious 

 and onerous measure. 7. It is also established that the best 

 method of treatment, if we view it from every point, never cures 

 more than one-third of the cattle attacked. And while we are 

 trying to cure the cattle in one stable, the malady, perhaps be- 

 nignant in a village where it has first appeared, is communicated to 

 another in a very deadly form. 8. Everywhere, when the system 

 of killing has been followed on the largest scale — in England (in 

 1 8 15), in Austria, and in the eastern provinces, for example — the 

 malady has been altogether destroyed; it exists, on the contrary, 

 wherever people obstinately persist in medically treating the cattle, 

 because then the infected centres become so extensive and so nu- 

 merous that it is impossible to purify them all. HoUand furnishes 

 an example. After the expose of the terrible destruction in that 

 country, the truth of which there can be no doubt, it is evident 

 that the most certain course to adopt is that of the slaughter of 

 not only the diseased cattle, but also the healthy ones which 

 have had communication with them; and to disinfect not only the 

 stables where the sick have been, but also those where the sus- 

 pected ones have dwelt. This strong measure stifles the pesti- 

 lential germ in its birth^ and does not allow it to be dev^eloped 

 anew.^ ^ 



In this year, according to Wirth, the contagious pleuro- 

 pneumonia of cattle appeared in France, causing much loss.^ 

 He alludes, I imagine, to the ^murie^ in Franche-Comte, just 

 described. 



The same writer informs us that the 'rot' [der Fdiile) ap- 

 peared in calves and other herbivorous creatures in the Canton 

 Zurich, and great destruction resulted.^ 



A.D. 1770. In this year the sugar ants made their first appear- 



' Vicq d''Azyj: Expose des Moyens Curatifs et Preservatifs, &c. Paris, 1776. 

 2 Wirt/i. Op. cit., p. 300. ^ Ibid. P. 123. 



