94 THE CONTAGIOUS TYPHUS 



1st. That we have no proof of any anato- 

 mical and physiological difference in the 

 humours or in the blood that is to say, in 

 the organic, intimate, and biological elements 

 of the individuals which collectively consti- 

 tute the bovine species. 



2nd. That we have a right to believe, that 

 all horned cattle are apt to develop the typhic 

 virus when they are placed within the condi- 

 tions required for that effect that is to say, 

 when they are exposed to the special morbific 

 causes which form its condition sine qua non, 

 and which are met with on the banks of those 

 great rivers which water Southern Eussia 

 and Hungary, in Africa, on the banks of 

 the Nile, in South America, on the margins 

 of the lakes, and in what are called hot cli- 

 mates, &c. 



II. 



But if the origin of the typhus cannot ex- 

 clusively depend on the peculiar organization 

 of certain individuals of the bovine species, we 

 must inquire after and search for the real 

 causes which produce it. 



