THE EPIZOOTIC DISEASES IN HORSES, CATTLE, &c. 339 
them have nothing to do. In the mean time, however, it is a 
malady which, not seeming to presage any evil, is propagated 
with incredible rapidity, and soon begins to threaten the flock 
with a degree of devastation as inevitable as it is astounding to 
those who have not observed its early symptoms. Favoured by 
a thousand unfortunate circumstances, the evil spreads from one 
pasture and from one farm to another, until it has established it- 
self over an immense tract of country. It surmounts every barrier 
with which we would afterwards fain oppose its fearful ravages, 
and seems to bid defiance to all human power and skill. 
“ Man, also, is exposed to contagion from many of these mala- 
dies, or to contract many serious diseases to which these epizoo- 
tics have given birth, the result of which is, too often, the loss of 
the greater part of the persons attacked, without its being in the 
power of the most skilful medical men to diminish the number of 
victims. Paulet observes that, out of ninety-two epizootics, of 
which records have been preserved, twenty-one were common to 
man and the inferior animals; and Buniva remarks, that out of 
twenty that have ravaged Italy and Sicily, eight have attacked, 
at the same time, both the human being and the brute. The 
study of these epizootics is, then, well worthy of our deep at- 
tention. Many celebrated physicians have not disdained to oc- 
cupy themselves in the study of these maladies, and to them we 
are indebted for the most interesting information, and the most 
valuable assistance in these sad moments of public calamity. If 
comparative anatomy is necessarily allied with that of man — if 
the relations of organization that exist between all the mam- 
malia establish between the larger animals and the human being 
evident analogies in all the physiological and pathological changes 
which take place, comparative pathology must offer results highly 
useful in the study of general medicine. The knowledge of the 
diseases of animals, when it becomes more advanced, will contri- 
bute to diffuse new light on the maladies of the human being, 
and, perhaps, bring to perfection the methods of cure or pre- 
vention, owing to the facility of multiplying on the inferior ani- 
mals experiments which we cannot attempt on the human being. 
“ The term Epizootic, agreeably to its etymology, comprehends, 
refers to, and embraces all the internal diseases, acute or chronic, 
of animals, from the moment in which the same disease begins 
to attack at the same time many individuals, whatever may be 
the nature, the duration, or the causes of the complaint. Arising 
from one common cause — more or less general, yet often un- 
known, or, at least, imperceptible to our view, or only apprecia- 
ble in some cases by their approach to certain known facts and 
the consequences which flow from them — epizootic diseases are 
