PLEURO-PNEUMONIA. 593 



Causes. The history of a plague, as it spreads from a centre 

 of origin, affords us the most certain data whereby to judge of 

 the influences capable of inducing the disease. Such a his- 

 tory must include the special facts brought out by the care- 

 ful study of the malady in special localities; but a truthful 

 picture of the source and extent of ravages due to a deci- 

 mating epizootic, may, for the purpose of affording a ready 

 and satisfactory glance, bring out in relief the greater inci- 

 dents faithfully recorded, without burdening the narrative 

 with irksome details. 



A malignant form of inflammation of the lungs, of an 

 eminently contagious character, and peculiar to the ox 

 species, has been recognised as having existed within the 

 memory of man in the mountainous regions of the centre of 

 Europe. There is every reason to believe that the malady 

 described by Valentin in 1693,* Jacob Scheuchzer in 1732, 

 Bucard Mauchard in 1745, and Kauch in 1778 and 1784, 

 was the same pleuro-pneumonia which has caused such 

 terrible ravages over Europe during the present century. 

 The cattle of the Swiss Alps, of Hesse, Swabia, and Upper 

 Silesia, were especially affected by the pestilence. The epi- 

 zootics reported by the ancients cannot be readily recognised 

 at the present day, from the meagre descriptions handed 

 down to us. Many are evidently outbreaks of malignant 

 anthrax, affecting man and beast. There is no such doubt, 

 however, hanging over the histories of the murrain under 

 consideration, as it was studied in Central Europe during the 

 early part of the eighteenth century. Wirth, one of the best 

 authorities on cattle plagues, says,-)- " Certain it is that it 

 (pleuro-pneumonia) manifested itself in the years 1713 and 



* Epliem. Natur. Cur. et Sydenham. Op. et Gen. 1, p. 276. 

 t Lehrbuch der Seuchen und Ansteckenden Krankheiten der Haust- 

 hiere. Von J. C. WIRTH. 2nd edition. Zurich, 1846. 



2 Q 



