458 
SOUNDNESS IN HORSES. 
but if such persons could only learn how imperceptible the transl- 
ions are from health to disease, and vice versa —how many varia¬ 
tions there are from nature which one regards as disease, while 
another, with apparently equal reason, views them as compatible 
with health, all surprise and illiberality of sentiment would vanish 
in the acknowledged intricacy and abstruseness of the subject. 
lo say that disease consists in “any alteration from a perfect 
state of health,” is no more than shifting the saddle off the back 
°f 011e . to P* ac . e u P on that of another: unless we possess 
clear and distinct notions concerning the healthful state, how are 
we to detect these “alterations,” which are said to form the 
essence of disease ? 
In regard to the healthy condition of a part, there are two points 
or view m which the question may be placed: either the part 
may be considered to be healthy or sound, because it continues 
in the preservation of its natural aspect , structure , and function; 
or, it may still be pronounced to be sound, although it no longer 
possesses its original appearance and structure, because it retains 
the functions natural to it. I may be told here, that alteration of 
structure supposes alteration of function, the one stake being in 
nature consequent upon the other. To which supposition ,\\\q 
short reply I would make, is this—that, if I am not to be allowed 
to estimate altered function by the senses—if I am to be com- 
pelled to admit that derangement to be present which the animal 
itself betrays no sign of, and which no observation can detect, 
and to admit it because there is demonstrable alteration of struc¬ 
ture—why, such an admission would not only carry me beyond my 
belief, but embark me upon an ocean of difficulties and per¬ 
plexities from which I could never hope to extricate myself. I put 
m my opinion, then, that an organ or a part may perform its 
functions, to the fulfilment of its design or end, although it 
has undergone alteration of structure; and I feel quite certain, 
it this is not the case, that we are on numberless occasions quite 
ignorant of the concomitant functional irregularity, even though the 
case be one of our own persons. 
For this reason, and for others which will be developed here¬ 
after, I mean to coniine my views of disease, in relation to un- 
soundness, to altered function ; and to altered function in a per¬ 
ceptible form. I wish to work upon plain matter of fact: on 
such an occasion as this I feel it my duty to cast away all hypo¬ 
thesis ; which would only lead me to adopt insecure conclusions, 
and perhaps beguile me into sophistry and subterfuge. 
Next, let me explain what is, or ought, in my opinion, to be 
understood by “alteration of function.” This, the common 
medical phrase, is couched in language that docs not alogether 
