436 INFLAMMATION. 



sphere, a large and firm coagulum was found in the medullary substance. It 

 was nearly circular, and measured, approximately, four centimeters in diam- 

 eter and two and one-half centimeters in thickness. It was situated a little 

 anterior to the center of the hemisphere, and did not anywhere encroach upon 

 the cortical substance. The contiguous brain substance was softened for 

 a thickness of about two lines, but the clot was removed almost entire, and 

 there was no serum, pus, or other indication of inflammation or of extensive 

 degeneration. No pathological changes could be discovered in the left hemi- 

 sphere. The fluid in the ventricles was not appreciably increased in amount, 

 although there was more serum upon the left than upon the right side. The 

 velum interpositum and choroid plexuses of the ventricles were highly vascu- 

 lar, the veins being turgid and swollen, and this was more marked upon the 

 left side. The tubercula quadragemina were manifestly degenerated, and 

 presented the appearance described as white softening. This condition was 

 much more evident upon the left side, but it was not limited to these bodies, 

 It also extended laterally and anteriorly, involving the corpora geniculata, the 

 posterior and inferior portions of the optic thalamus on the left side, and also, 

 to some extent, the floor of the fourth ventricle. A portion of the left optic 

 tract and the adjacent under surface of the thalamus was removed for micro- 

 scopical examination. This was so soft as to require very careful handling to 

 prevent crushing." 



Dr. Linnell kindly sent me a portion of the under surface of the left optic 

 thalamus, which came to me preserved in alcohol. The specimen exhibited a 

 grayish-yellow discoloration, as if fatty. It was placed in a one-fifth per 

 cent, solution of chromic acid, and after a few days was sufficiently hard to 

 be sliced with a razor. The sections were mounted in glycerine, and even 

 those which went through the treatment with alcohol and oil of cloves were 

 again introduced into water and mounted in dilute glycerine. 



Incidentally, I wish to say that, for three years, I have been pursuing 

 microscopical studies in the laboratory of Dr. C. Heitzmann, and by repeated 

 trials have become convinced that the mounting of specimens in glycerine is 

 far superior to mounting in Canada balsam or Damar varnish. Comparative 

 mountings in these liquids, especially for specimens of the nervous centers, 

 have resulted in the conviction that the balsam or varnish mounting ought to 

 be wholly abandoned. Unquestionably one, if not the main, reason why our 

 knowledge as to the pathology of the brain and the spinal cord has progressed 

 so slowly for the past twenty years is the mounting in balsam. By this method, 

 the specimens in a short time clear up to such an extent that the minutest details 

 fade, and the specimens become unfit for research with high amplifications of 

 the microscope (800 to 1200 diameters), which are the only possible means 

 of revealing the minutest normal, as well as pathological, features. 



All the specimens obtained exhibited a peculiar change of the gray sub- 

 stance. This consisted in the presence of homogeneous, grayish fields of 

 greatly varying size and configuration, mostly with fluted outlines, scattered 

 throughout the gray substance. With lower powers of the microscope, I was 

 satisfied that these shining fields either accompanied capillary blood-vessels, 

 or were distributed without any regularity in the gray substance, or, lastly, 

 represented more or less straight tracts in closely lying parallel or in diverg- 

 ing fan-shaped courses, in the direction of the axis-cylinders. The latter feat- 

 ure was especially pronounced in the neighborhood of the optic tract. (See 

 Fig. 180.) 





