THE 
MONTHLY MICROSCOPICAL JOURNAL. 
SEPTEMBEE 1, 1876. 
I. — A New Process of Preparing! and Staining Fresh Brain for 
Microscopic Examination. By Be van Lewis, F.E.M.S., Patho- 
logist and Assistant Medical Officer, West Eiding Asylum. 
{Taken as read lefore the Eoyal Microscopical Society.) 
Plate OXLIX. 
It has always appeared to me a matter of very essential importance 
that the microscopical examination of the brain should involve 
some process applicable to immediate use, and that we should not, 
as is so often the case, rest content with its microscopic appearances 
until the lapse of six or eight weeks has prepared the brain sub- 
stance for examination by the ordinary processes of hardening and 
section cutting. 
The earlier our examination is made after death the more probable 
is it that minute lesions will be detected and fallacies eliminated 
which are necessarily involved in processes more complicated and 
prolonged. In advocating a method which I now adopt for the 
examination of fresh brain I would wish my readers to fully under- 
stand that I do not for an instant assume that any such process 
can possibly supersede the now venerable method of hardening by 
chromic acid and its salts. Both methods should be employed in 
all cases, for each has its individual merits ; thus the older plan 
preserves to us most faithfully the natural relationships of indi- 
vidual parts, which cannot be said for the new process ; on the 
other hand, we gain by the fresh examination far greater details 
of structure and differentiation of the various constituents, besides 
other advantages naturally attendant upon so early an investigation. 
It will therefore be evident that whilst for researches in comparative 
histology the hardening reagents must be employed, for many 
purposes, especially pathological, the fresh method has its special 
advantages. In the pathological department of West Eiding 
Asylum I have enjoyed especially good opportunities for thoroughly 
testing the question whether or not a process could be devised for 
examining in the fresh condition the structure of the cerebral and 
cerebellar cortex. I have no doubt that in this investigation I am 
working side by side with others equally anxious to solve the 
VOL. XVI. I 
