PROCEEDINGS OF SOCIETIES. 
41 
Medical Microscopical Society. 
Friday, May 21, 1875. — Dr. F. Payne, President, in the chair. 
Fatty Degeneration of Muscle . — Notes on this subject were read by 
Dr. Kesteven. He observed that the expression “fatty degeneration,” 
as usually employed, was a misnomer ; that the change is one in 
which, as a matter of fact, fat plays no part at all. Instead of fatty 
matter, the degenerated muscles exhibit a disintegration of the con- 
tents of the muscle fibrils, obliterating their striation. Along the 
centre of these are to be seen dark-brown or black granules of a pig- 
mentary character, not removable by aether or alkalies. The change 
begins and ends in the fibrils, and is very distinct from the fatty 
condition, in which the fibrils retaining their striation are separated 
by deposition of adipose tissue. The latter form of disease is more or 
less associated with changes in the nervous centres, while in the 
former it is not so. Preparations and illustrative drawings were 
exhibited by the author, of muscular atrophy, pseudo-muscular hyper- 
trophy, rupture of the left ventricle, infantile paralysis, and the so- 
called fatty degeneration. 
The President and several of the members took part in the dis- 
cussion that followed. 
Myelitis . — A paper on this subject, by Mr. D. J. Hamilton, was 
read by the President. The author pointed out that much uncertainty 
existed as to the real character of the various lesions of the spinal 
cord, known as hardening, softening, sclerosis, disintegration, &c., and 
more especially as to their connection with the secondary changes 
depending on loss of the trophic influence by nerve-cells on the fibres 
to which they are attached ; and as to their connection with inflam- 
mation. 
In order to elucidate the latter point, it was necessary to know 
definitely in the first place what changes inflammation does produce 
in the spinal cord ; and with this end the author made the experiments 
recorded in his paper. His method consisted in first producing a 
lesion known to be inflammatory, and then examining the morbid 
appearances, all preconceived ideas on the subject being purposely 
laid aside. All appearances were verified by abundant repetition, and 
only those which were found to be invariable were recorded. The 
experiments were conducted in Professor Strieker’s laboratory at 
Vienna. The method of experimenting was : A small animal, as a 
cat, having been narcotized, the spinal cord was cut down upon at the 
junction of the dorsal and lumbar portions, and a thread passed 
through for about an inch in a longitudinal direction. The wound 
was now closed, and the animal killed after forty-eight hours, by 
which time inflammation was abundantly set up. The cord was then 
cut up into pieces an inch long, hardened in chromic acid and spirit, 
and kept at a low temperature. Sections were made in a microtome, 
stained with carmine and mounted in dammar. 
When examined, the tissue at the seat of lesion was found broken 
down, and showed numerous extravasations of blood ; but the true 
inflammatory area was seen at a little distance from this, being gene- 
