THE HISTORY OF VETERINARY MEDICINE. 255 



attention, have been made in France. It is necessary, nevertheless, 

 to remember that the plague attaches itself by preference to the 

 wool and the hair of animals, that it may be transported by these 

 materials, and that they will spread the contagion to other towns 

 and countries free from the contagion. It is, then, possible that 

 the poisonous exhalations of the diseased beast attach themselves to 

 the hairs of animals which go near it. It is at least certain, in our 

 country, that as often as the disease is manifested among cattle, and 

 when it has been traced to its source, it has been found that a beast 

 which has been purchased in the market of some suspected place, or 

 which had been brought from some suspected locality, has carried 

 the contagion with it to a new center. Sometimes, also, the cattle 

 of our regions have been pastured with those of a neighboring in- 

 fected country. It is very probable that at other times the air of 

 the infected mountains has spread the dangerous exhalations over 

 the country. We believe that we have observed that healthy cattle 

 which had smelled of those that were diseased have shown, a few 

 hours after, traces of the contagion. It is known that the ship from 

 Sidon brought the plague to Marseilles, and that the bull which was 

 taken from Hungary to Padua, in 1711, took with it the fearful con- 

 tagion which first ravaged Italy, and then nearly the half of Europe. 

 It thus appears that the plague of man and the cattle-plague take 

 their origin in hot countries, that they can infect temperate regions, 

 and that they are gradually destroyed during the cold of some rig- 

 orous winter. That which is yet a better proof that the pneumonia 

 is perpetuated by infection, as the plague is, is the manner in which 

 we can confine it in suspected places, and by cutting off all commu- 

 nication between the stables which are infected and those which are 

 not. If this malady were generated spontaneously, like the ordinary 

 fevers of man, we would in vain barricade stables, in vain would we 

 slaughter the cattle of a village, and it would be useless to isolate 

 the mountains by barriers and guards. All these precautions would 

 not keep away a disease which has its origin in the blood itself of 

 the healthiest cattle. . . . The contagion, however, does not spread 

 very far, and it does not infect a column of air for any great distance. 

 If the air were infected, if it was able to carry afar the poison of 

 the disease, the barriers and other precautionary measures of man 

 would be unavailing. In this there is the greatest resemblance be- 

 tween the disease of cattle and the plague of man. The monks and 

 nuns of Marseilles were saved because they kept their convents 

 closed. The air was not, then, the cause of the disease, else the clos- 

 ing of the convents would not have prevented the pestilence from 



