408 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Voxt. VI. 
parts of sublimate saturated in ninety-five per cent. alcohol and of a two 
per cent. solution of potassium bichromate in water. Small pieces were 
left in the freshly prepared mixture for two to four hours, washed in fifty 
per cent. alcohol, and then passed through the grades of alcohol. 
Material intended for chemical investigation was fixed in alcohol. The 
cells obtained from alcohol fixation are not materially different from 
those obtained with other fluids. The cone of origin and the process of 
spinal ganglion cells have nearly the same appearance in well preserved 
alcohol tissue that they have in sublimate material. Flemming’s failure 
to get good results with alcohol may have been due to the circumstance 
that he did not leave his tissue in the alcohol for a sufficient time. 
Three daysin alcohol as in Flemming’s” method is not enough to insure 
complete coagulation of the proteids of the cell. 
After fixing and hardening the material was imbedded in paraffin, 
using oil of bergamot for infiltration. Sections were attached to the 
slide by the distilled water method and stained. 
I1—THE STRUCTURE AND MICRO-CHEMISTRY OF THE NERVE 
CELLS OF MAMMALS. 
It is generally believed that three substances enter into the formation 
of the body of nerve cells: (1) the Nissl granules, (2) a spongioplasm 
that is generally believed to be fibrillar but which may be reticular, and 
(3) a hyaloplasmic ground substance in which the two former are em- 
bedded. As this structure is found in the nerve cells of mammals and 
the nerve cells of this class have been most frequently studied, they will 
form the subject of this section. 
Material was used from the following animals :—man, ox, pig, sheep, 
dog, cat, rabbit, guinea pig and mouse. In most cases pieces from the 
cortex, cerebellum, cord, spinal and sympathetic ganglia were obtained 
and fixed in various fluids, but by preference in alcohol and the bichlor- 
ide-bichromate mixture. The shape and distribution in the cell of the 
Nissl granules are best demonstrated by staining sections fixed to the 
slide for a few minutes in an aqueous solution of toluidin blue or methy- 
lene blue, but preferably in toluidin blue, which v. Lenhossek regards as 
a specific stain. After staining, the sections are differentiated in a mixture 
of aniline and alcohol, cleared in oil of bergamot and mounted in balsam. 
The results obtained with this method are similar in every respect to 
those obtained with the more laborious process of Nissl. 
15 L. c.; p. 385. 
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