47^ History of Animal Plagues. 



some experiments in 1775 on animals of the same and of a dif- 

 ferent species ; the symptoms and the danger were the same in 

 oxen ; three sheep died after inoculation ivithout taking the dis- 

 ease, in consequence of the gangrene which ensued ivhere the 

 wounds had heen made. The only difference between the results 

 of all these experiments is that the Marquis de Courtivron tries 

 to disabuse the public mind of an opinion which has already 

 cost the world so much — the belief that when an animal has once 

 had the disease it is safe afterwards ; whereas Vicq-d'Azyr en- 

 deavours to assure them of its truth. What is, then, the con- 

 clusion to be derived after so many experiments and researches 

 conducted with so much labour and cost? Have we no re- 

 sources against such a pestilence? It is only too true that 

 we have few ; but we have acquired a precious truth notwith- 

 standing, and that is the inutility of employing any of these 



means The actual malady is a species of pest, which has 



not perhaps its exact analogue in the human species (dont il n'y 

 a peut-etre pas d'exemple scmblable, a la rigueur dans Pespece 

 humaine). It is an acute, pestilential, piitrid, and gangrenous fever, 

 or, if we like it better, an ardent malignant fever, fomented by 

 a deleterious and contagious principle, of an erysipelatous nature, 

 capable of producing an inflammation or gangrenous phlogosis 

 in cattle, and infecting their humours, and whose chief seat is the 

 upper air and digestive passages, the brain and the spinal cord, 

 and generally the whole nervous system, particularly at its origin; 

 and which is proved by the extreme sensibility, especially about 

 the spine, the loss of power, and the state of the viscera. If it 

 were permitted to draw an analogy, we might compare the acci- 

 dents that the animal experiences to the effects of certain poisons, 

 which, while they act directly on the tracks they are in contact 

 with and cause a gangrenous inflammation, carry their action 

 at the same time to the nerves, causing stupor, tremblings, 

 convulsive movements, apoplexy, &c. ; while others infect the 

 blood, lymph, and the nervous fluid without sensibly injuring 

 the dicrestive canal.^ 



It is supposed, as already noted, that this last attack of Cattle 

 Plague cost France 150,000 animals, valued at about 150,000,000 

 francs. 



