MICROBES AND CONTAGIOUS DISEASES. 
353 
the most favorable circumstances for the even development of 
an organism so far-reaching in its influence as the hoof. It can 
never be grown as a hot-house plant, but must have constant tear 
and wear on suitable ground; this is an indispensable factor in 
its cultivation. This the breeder must fully understand; some parts 
of his farm may be as unsuitable for his colts to run in as a 
swamp would be for wheat, and yet he may have within its limits 
fields admirably suited to their wants, if judiciously used; if to 
this is added a knowledge of when to use the rasp or paring 
knife, with perhaps some simple application, less will be heard of 
heroic operations, fiery tortures and the mysterious remedies of 
the past. 
I think it is Herbert Spencer who says: “We want all facts 
which help us to understand how a nation has grown and organ¬ 
ized itself.” This applies as well to the horse’s feet. I sincerely 
hope that the study of this subject will be taken up by the pro¬ 
fession with an enthusiasm which will lift it to the position its 
importance demands, and that it will be thought worthy of the 
best efforts of our brightest men. 
o 
MICROBES AND CONTAGIOUS DISEASES. 
By M. Trouessart.* 
The parasitic theory of contagious diseases is far from obtain¬ 
ing the assent of all medical men. In fact, it has thus far en¬ 
countered strong opposition from men high in authority, who 
have become the champions of the counter theory of the inneity 
of diseases. In their view, disease develops itself spontaneously, 
or at least, under the influence of a contagium whose nature is 
yet unknown. They hold that when microbes are discovered in 
the blood of patients, it is only as a secondary complication ; they 
are not the cause of the disease, and are neither the contagious 
* From the Revue Scientifique , Feb. 26, 1885. 
