114 ON AN APHTHOUS AFFECTION AMONG CATTLE. 
partly marshy, and unwholesome ; at a period when the animals 
were abandoned, without any care or treatment, to the efforts df 
nature alone. The diseases prevailing at such a time must neces- 
sarity derive a certain degree of malignity from such a deplorable 
state of things, and be attended with certain complications now 
no longer to be seen. This view is, we think, fully demonstrated 
by the analysis already given of some passages in ancient authors. 
If further proofs are required, we would add that, since agriculture 
has become so greatly improved, and veterinary knowledge dis- 
seminated throughout the country, those devastating epizootics 
which formerly committed such fearful havoc throughout Europe 
are no longer heard of. 
After reading the works of old medical authors, we become, if not 
wholly convinced of, at least very much disposed to believe in, the 
non-contagiousness of aphthous affections ; and this belief, espe- 
cially when we have not had an opportunity of personally ob- 
serving them, appears corroborated by their sudden appearance in 
a great number of animals, by their rapid progress, and by the 
type peculiar to epizootic and contagious affections. These are, 
we must confess, characters that may, at first sight, impose on a 
casual observer, or one who merely judges from external appear- 
ances ; but they cannot influence the opinions of those who possess 
any physiologico-pathological knowledge. The thing is so self- 
evident that, from the time veterinary science shook off the yoke 
of ignorance and prejudice, and included in its domain the various 
branches of natural history, doubt has taken its flight from nearly 
every mind. Messrs. Fabre, Maret, and Levrat are the only 
individuals among all our veterinary cotemporaries who have 
positively asserted that these affections are in the highest degree 
contagious. According to M. Maret, contact with the diseased 
animals is by no means necessary : any man who has entered an 
infected stable is capable of carrying contagion to distant places. 
Without having the least intention of casting any imputation on 
the veracity of our brethren, we must be permitted to doubt 
whether the subtilty of the aphthous virus can be so great as to 
enable it to impregnate the garments of those persons who tend on 
the diseased animals. And, admitting this to be true, a prac- 
titioner ought, most explicitly to develope all the circum- 
stances and facts of cases on which he pronounces a positive 
opinion. To state, as M. Maret does, that an affection is contagious 
because all the animals in a certain stable were attacked by it, 
although it was first developed in only one, is no proof of great 
pathological powers. Why should the causes act on one animal 
in preference to another ? Why should they have spared or at- 
