45 o History of Animal Plagues. 



the flesh of those beasts cannot be constantly vitiated, for in 

 those countries where measures of pohce are neglected, the poor 

 people eat the flesh of infected oxen. We have scarcely observed 

 the odour of the skins, but they have been found of a softer 

 texture than in an animal in health. In other countries, ab- 

 scesses have been scattered under the whole surface of the skin, 

 and some doctors have regarded them as a salutary evacuation, 

 but nothing similar has been observed in the contagion of this 

 country. It is more common to find a yellowish fluid in the 

 cavity of the chest, but this is not constant ; and we have opened 

 cattle which had one side filled with this fluid, and none on 

 the other. The country people have distinguished two kinds of 

 pneumonia, the dry and the humid, but there is no foundation 

 for this distinction. 



4- 

 ' The true nature of a disease is known by the accidents which 

 accompany it in its duration, and by the changes which we ob- 

 serve on the autopsy of the animal, when compared with the 

 organs of the body in health. But the essential features of the 

 disease ought to consist in the symptoms which are manifested 

 from the beginning, and which have continued during life ; and 

 in the marks of corruption in the interior w'hich are the actual 

 causes of these symptoms, it requires care not to be deceived by 

 these accidents, which are a consequence of the corruption of 

 the humours, and are only most apparent in the later stages of 

 the disease. It is believed that the contagion amongst the cattle 

 is an inflammatory fever; a malignant fever; a fever accompanied 

 by an eruption on the skin; as well as an inflammation of the 

 stomach. The ancients have got very near the truth, and the 

 vulffar have known the nature of the disease better than the 

 learned. It is evident that it is a disease of the lungs, which 

 commences by an inflammation, running often into gangrene, 

 at other times into abscesses, and which terminates in phthisis. 

 It is very astonishing that amongst the number of modern 

 doctors who have written on a contagion existing for so many 

 years, scarcely one has observed that the seat of the disease 

 exists in the lungs, or even that these were attacked. 



