Vlll PREFACE. 



lible criterion for ascertaining the position 

 which a nation occupies in the scale of civili- 

 zation, and the value of its religious, social, 

 and political institutions. 



Calamities always leave behind them dis- 

 asters and victims, but they bequeath also a 

 precious legacy. Nations which are called 

 upon for fresh and progressive efforts, find 

 in the experience they have gained a new 

 source of strength and means of future great- 

 ness. I am convinced that this will be the 

 case with England; though, helpless for the 

 moment, and unable to stay the Cattle Plague 

 which now ravages her entire extent, she will 

 in future be found better prepared to resist 

 the inroads of such a direful enemy. 



No branch of human knowledge has been 

 more rudely tested during the present epizootic 

 than medical science. Many persons have been 

 astounded at its helplessness ; but if they had 

 reflected at what a distance medicine has to 

 follow in the wake of the exact sciences by 

 which it is furnished with instruments for 



