816 PRACTICE OF VETERINARY MEDICtNE AND SURGERY. 
facts, and acknowledged inferences, drawn from observation 
and experiment. 
For this reason we shall leave untouched the consideration 
both of those complex vital processes whose phenomena, more 
or less combined, constitute disease, as irritation, congestion, 
inflammation, degeneration, atrophy, &c., and the examina¬ 
tion of the varied and differing materials which are met with 
as the ultimate or constituent elements of disease—matters 
pertaining specially to the department of pathological his¬ 
tology and chemistry. 
Methods by which Disease may be elucidated and 
understood. 
As students of special pathology we will find that disease 
in those animals with which we are called upon particularly 
to deal is, in our case, to be studied in two different characters 
or aspects. 
1st. As those diseases present themselves to our notice 
and consideration in separate, distinct, and individual cases 
and animals. 2nd. As they form, or constitute, or are 
gathered or grouped into particular classes or genera of disease, 
sytematic study. 
Of the first method of instruction or investigation we 
shall say nothing further here or at this time, except to 
bring prominently under your notice that, taking into con¬ 
sideration the exceptional advantages enjoyed by this Col¬ 
lege, it has been determined to give to this method of acquiring 
sound practical knowledge of equine medicine and surgery 
well-considered attention. 
In whatever character or aspect, w r hether clinically or 
according to any system of medical classification, we, as 
students or practitioners, make examination of disease, there 
is always a certainty that a perfect similarity of subjects or 
problems will be placed before us for consideration. There 
is, as Aitken says : 
“ 1st. The morbid phenomena or symptoms by which we 
become aware that derangement has taken place in the 
economy. It is by a mental effort that either the student 
or the physician converts these symptoms into signs of 
disease ; and hence arises the necessity of studying sym¬ 
ptomatology or semeiology. 2nd. The agents by which de¬ 
rangements and diseases are produced or brought about, 
constituting the department of etiology. 3rd. The seats or 
localities of disease or of derangements constituting patho¬ 
geny. Here the peculiar nature, general forms, and types 
of disease must be studied, together with varieties in their 
