404 THE PROGRESS OF VETERINARY SCIENCE. 
Foremost among the advances in our science and art is 
the application of histology and physiology to pathology. 
The time has now arrived when the history of a case or series 
of cases will not be considered complete unless the microscopic 
appearances be given ; and justly so, for it promises to be the 
only instrument capable of ascertaining the minute tissue- 
changes which take place in diseased and healthy organisms, 
hence its importance and necessity in a collegiate course. 
By the aid of the microscrope we have been able to deter- 
mine that the active element in vaccine lymph consists of 
minute particles not exceeding - 2 -o Wo of an inch in diameter, 
and that two of the most destructive of epizootic diseases, 
variola ovina and glanders, are dependent for their existence 
and propagation upon extremely small living solid particles, 
to which the title of mycrozymes is applied. An animal 
suffering under either of these diseases is a source of infection 
and contagion to others, for precisely the same reason as a 
tub of fermenting beer is capable of propagating its fermen- 
tation by “ infection ” or “contagion” to fresh wort* By 
its use we have ascertained that the vesicular epizootic, or 
foot-and-mouth disease, is of a fungoid nature, and owes its 
virulent contagious character to the dissemination of the 
spores of a cryptogamic plant ; while the beautiful discovery 
of the propagation of the itch acari, the character of the 
several tinea in man and animals, are. no less the proofs of its 
utility, to say nothing of its use in renal diseases ; indeed, its 
uses and revelations are legion, and would weary by repeti- 
tion. Truly does Mr. Fleming say — “ That no anatomist, 
physiologist, or pathologist, deserves the designation who is 
unacquainted with its use and discoveries.” It is remarkably 
easy for Mr. Fleming, or any other of Her Majesty’s men, 
the Professors at our Colleges, or even those having large town 
practices where they can conduct the principal part of their 
business on their own premises, to become experts in its use 
and profit accordingly ; but it it is another and very different 
matter for the great body of hard-worked country practitioners, 
to sit down after a hard day’s ride, or get up after a late night’s 
work, to prepare specimens and contract their pupils to look 
at them, and derive any benefit therefrom. We must be con- 
tent, therefore, to accept the teachings of those favoured indi- 
viduals, and return them our thanks for their labours in our 
behalf and in the interests of science. 
In the matter of teaching, great advances have lately been 
apparent. Formerly it consisted of, or was confined to, a dry 
detail of symptoms, without attempting to connect them with 
* Huxley. 
