IN THE HORSE. 
257 
ullected; whereas those of annihilation of the functions of voluntary 
motion and sensation, on the other hand, proclaim the morbid alteration 
essentially to exist in the substance of the brain itself.’^ 
Furthermore, this chronic irritation is the most frequent 
cause of the vices inherent in certain horses, such as shyness, 
restiveness, impatience, biting, kicking, i, c. without provoca¬ 
tion. /In fine, it is equally influential in the nervous affections 
observable in the sense of sight, and principally in amaurosis or 
gutta serena,' 
If we except severe lesion and external violence, the causes 
of morbid super-excitation of the encephalon, either direct or 
sympathetic, in place of giving rise to cerebral congestion, pro¬ 
duce only functional disorder—inordinate vital energy, and that 
kind and degree of irritation in the membranes which ends in 
serous effusion, principally into the ventricles. 
“ XI. We have had occasion before to observe, that this serous ex- 
lialation, when moderate, is compatible with the normal state of the 
parts, and even inseparable from their perfectly healthy condition. It is 
only in cases wherein it is too abundant, or its quality is deteriorated, 
that there can be said to exist disease.’^ 
This morbid irritation is, doubtless, a pathological condi¬ 
tion arising from stimulating causes, and one approaching to 
phlegmasia; but so long as it is confined to the production of 
super-excitation, functional disorder, and morbid serous ex¬ 
halation, it cannot be regarded in the light of confiraied in¬ 
flammation. As the presence of serosity in the ventricles, 
although an effect of morbid irritation, becomes the principal 
cause of the symptoms accompanying, characterizing, and an¬ 
nouncing this irritation of the brain and its membranes, it is not 
repugnant to the principles of sound pathology to preserve the 
name of Hydrocephalus, and to consider it as a distinct disease 
of the brain, contrai y to the too exclusive opinion lately broach¬ 
ed by M. Rostan. 
t 
“XII. This w'ould render these who were ignorant of the proximate 
causes of hydrocephalus liable to mistake the efl’ect for the cause of the 
disease, and to reeeive a contingency purely seeondary for the name of 
a disease of w'hich it only constituted one of the effects, instead of dis¬ 
tinguishing it by the part affected. In regard to the exclusive opinion of 
M. Rostan, it is not easy to say whether he ever asserted thus mueh or 
not, since the name of the w^ork is not mentioned: I must avow niy owai 
disbelief of it, for in his work on mollities cerebri, w e read at page 303, 
‘It seems to me that authors who have treated on these disorders, by 
whatever name they may have distinguished them, have mistaken the 
consequence of the disease for the disease itself. The names of hydrO’- 
cephalic cerebral fevers^ serous apoplexy, acute and chronic hydrocephalus, 
can only mean an aeute or chronic inflammation, or an organic alteration 
of the brain or its membranes, terminating in an effusion of serosity be¬ 
tween the membranes or into the ventricles.’ 
2 G 
