COMA IN THE HORSE. 
325 
such had shewn itself. I administered a dose of opiate and diffu- 
sive stimulant medicine : the poor animal, however, rapidly got 
worse, and about one o’clock on Friday morning, being completely 
exhausted, he was compelled to yield to the grim tyrant, Death. 
Sectio cadaveris, Friday evening. — The contents of the abdomen 
healthy, with the exception of the liver, which was of a dark blue 
colour, but not otherwise altered. In the thorax were found about 
five or six quarts of transparent serum, of a yellowish colour, 
without any particular odour ; the pleura costalis and pulmonalis 
thickened, but not inflamed, except at one part, where the former 
was considerably inflamed for about the space of a foot ; the paren- 
chyma of the lungs was healthy, and I cannot now consider but 
that the pain which the horse suffered during the last six or eight 
hours of its existence was in consequence of the disease of the 
brain. The diaphragm was healthy. 
The brain was next examined, in which the only evidence of 
disease was that of an accumulation of, I should say, not less 
than two fluid ounces of serum in the lateral ventricles, together 
with, in the left ventricle, the tumour which you now see, and in 
the right another tumour of the same description, only three times 
as large (the one inclosed weighing when taken out exactly half an 
ounce , and the other one ounce and a half), and in its centre it had 
about a teaspoon ful of serum. Both tumours were attached to the 
plexus choroides ; the ventricles were, of course, enlarged to a con- 
siderable extent, and, as a consequence, the substantia medullaris 
was proportionately absorbed. 
The structure of the tumours is peculiar. I have examined one 
of them under the focus of a microscope, and consider it to be 
made up of small sacs, the cavities of which contain serum, and a 
vast number of very small metallic looking substances; (or, to the 
naked eye, they do not appear unlike the scales of fish), but under 
the microscope they are seen to consist of infinitely minute crystals. 
The bulk of the tumour principally consists of a substance appa- 
rently analogous to the fibrine of the blood, and of which the sacs 
already alluded to appear to be formed ; and the whole is enclosed 
in a very thin transparent membrane. The tumours were highly 
vascular. 
Such, Sir, is a brief outline of the case, and which, so far as my 
reading and observation go, is the first of the kind on record. 
There is, however, a kind of semicartilaginous glandiform sub- 
stance said to have been found attached to the plexus choroides in 
the human brain ; but the tumours found in the present case do 
not belong to that class. I think the chemical composition of 
these malformations would prove an interesting inquiry, and, in 
the hands of a scientific analytical chemist, might throw some 
