THOUGHTS ON LAMINITIS. 253 
exertion ; 2d, to being kept too long in a state of inaction ; 
and 3d, to metastasis. 
It is my intention, in the present instance, to make a few 
remarks on these hypotheses generally , and on metastasis in 
particular j for it is one of those complex and ill- defined 
occurrences or freaks of nature extremely difficult to under- 
stand ; for when we witness a patient labouring under what 
appears to be a severe attack of pneumonia, or enteritis, and 
just in the midst of his sufferings we perceive a sudden 
cessation of those symptoms, and he all at once becomes as 
it were transfixed to the ground and unable to move, we may 
very naturally ask ourselves, where is the original disease 
gone to ? The animal is now, alas, lame enough ; but where 
is the original disease ? It has disappeared as if by sleight of 
hand. But the word metastasis is to my mind a most 
unsatisfactory way of meeting the difficulty. It is a vague 
and unmeaning term ; it explains nothing. Would it not be 
a better definition to say, that the system being surcharged 
with a superabundance of a vitiated, pernicious principle, 
which appears to be floating about in the vital fluids, and 
which becomes attracted to the feet, probably by a prepon- 
derance of electric influence; there must exist a strong 
susceptibility, or affinity, in the laminal tissues to attract 
this pernicious principle to them? — a sort of appetency, 
which overrules and concentrates itself. The partial or 
temporary settling upon the lungs or intestines was unnatu- 
ral — was artificial, they being at the time in a state unsuit- 
able to the location of this vacillation of inflammatory diathe- 
sis. This uncongenial state of the system is, as yet, an 
undefined enigma. Few persons think at all about an agency 
which, though fatal in its ultimate results, is followed by no 
immediate effect; the predisposition, however, once esta- 
blished, any circumstance may become an exciting cause ; but 
because this latter is nearer to the effect, it at once attracts 
the attention and fixes the observation, and thus often 
the true delinquent remains undiscovered. Yet there is at 
work, unobserved, an internal mystical agency that gives a 
preponderance, and conduces to this selection ; and this 
partiality is, I am persuaded, governed by certain laws, the 
investigation of which would amply repay the diligent 
physiologist. 
It is essentially an idiopathic disease ; for if that peculiar 
and favorable condition of the system does not exist, the 
horse with good feet, properly attended to, may be rattled 
along the hard road at a terrific pace, as long as you like in 
reason ; or he may stand inactive as long as you please ; or 
