894 PRACTICAL CHEMISTRY APPLIED TO VETERINARY SCIENCE. 
lie irritated points become red in a variable extent, in pro¬ 
portion as the cryptogams are few or numerous; and wlien 
they have finally penetrated the texture of the membrane, 
they provoke a reaction in the organism, manifested by fever 
and the aphthous eruption, the object of which appears to 
be only to eliminate the parasite, to remove it from the soil 
into wdiich it has fixed itself, and expel it from the body. 
The presence of the aphthse produces pain, renders mastica¬ 
tion and deglutition difficult, opposes locomotion, &c. The 
tissue of the cicatrice that gives it its pseudo-membranous 
aspect is only formed in part by the spores and tubular 
filaments of the parasite, mixed with isolated epithelial 
cells. 
Such is the nature and, it might be asserted, the origin of 
this troublesome epizooty; and the researches of Hadinger 
enable us to readily understand many points connected with its 
pathology, treatment, and panzootic tendencies, which cannot 
be so satisfactorily accounted for by microscopical examina¬ 
tion of the blood or milk. 
PRACTICAL CHEMISTRY AS APPLIED TO 
VETERINARY SCIENCE. 
By James Mason Broad, M.R.C.Y.S., Bristol. 
I AM so convinced of the importance of a knowledge of 
practical chemistry to a veterinary surgeon, that I am in¬ 
duced to write you a few lines which may perhaps encourage 
students to pay a little more attention to this most important 
branch of the veterinary art; at present I am afraid it is 
sadlv neglected. 
o 
During the time I was a student in veterinary medicine at 
the Ecole Veterinaire, of Alfort, Paris, I had great opportu¬ 
nities for studying the practical branch of chemistry, termed 
analysis, in the splendid laboratories of the college, under the 
supervision of Professor Clemence. Students there are, of 
course, obliged to go thi'ough the regular routine of practical 
chemical instruction, having to attend so many hours a week, 
and to analyze various portions of organic and inorganic 
matters; some of wdiich are purposely poisoned, as directed 
by the laboratory assistant, which position is filled by a senior 
student, who has previously proved himself well informed ; 
they are all consequently, upon leaving the college, for all 
practical purposes, good chemists. 
