FURTHER REMARKS ON CORONITIS. 
681 
from reasons obvious to every anatomist — the over-fatiguing of the 
sensible laminae and consequent inflammation of them, from their 
having to support the whole of the superincumbent weight of the 
animal during progression : nothing, however, can be said of the 
coronary substance having any such laborious function to perform, 
any more than has the sensible sole or frog. Experience, how- 
ever, teaches us that the coronary substance often becomes de- 
ranged or diseased after the animal has been subjected to this ill 
usage, and our attention necessarily is directed to inquire how this 
is brought about ; and investigation, I contend, will not admit of 
the conclusion, that the coronary substance is in any way more than 
sympathetically or secondarily affected. The sensible laminae are 
the only parts directly injured by the above cause, and the nature 
of the disease inflicted is either acute or sub-acute inflammation. 
When acute, it generally speedily terminates in one of two ways, — 
either by resolution and quick recovery, or effusion of a peculiar 
plastic material and perpetual lameness. But when the injury in- 
flicted has not been more than of sufficient intensity to produce 
laminitis in a sub-acute form, the ultimate effects will be materi- 
ally altered ; for here the vessels are not surcharged to that degree 
to cause effusion to take place, nor is the pain of that intense na- 
ture to cause the animal to lie down, and thereby rest the diseased 
structures : but the peculiar connexion of a sensible (most acutely 
so when inflamed) with an insensible inelastic substance, whereby 
swelling is wholly arrested, cannot but cause the disease, however 
trivial it might be considered in other situations, to continue for 
indefinite periods, and to be liable to continual fluctuations. Let 
us now inquire how this condition of parts will affect the surround- 
ing secreting surfaces ; and we shall find that this sub-acute in- 
flammatory action, existing in the sensible laminae, concentrates an 
undue quantity of nervous energy in them at the expense of the 
parts most approximated : first, the coronary substance ; next, the 
sensible sole, and then the sensible frog ; and just in accordance 
with their relative positions with the diseased parts do we find 
them to differ with respect to loss of tone and vigour during 
the continuance of the primary disease. This loss of stimulus and 
energy, sustained by the secreting surfaces of the foot, not only 
causes a diminished quantity of horn to be secreted, but that also 
of an abnormal quality : and this, of course, must continue to be 
the case until the primary disease is entirely dissipated, and an 
equilibrium of the nervous energy restored. 
“ Standing upon hot dry litter,” and “ being ridden into cold 
running water in hot weather,” are two causes which ultimately 
tend to the production of the same effects as the preceding one ; but 
the next two, “ being ridden into deep gravelly soils, or through 
