1894.] Microscopy. 827 
A Rapid Method of Hardening and Sectioning.’ —Every D 
practical pathologist must be convinced of the great importance, in i t 
many cases, of at once supplementing and completing the naked eve 
examination of struetures by a thorough microscopic examination. 
Microscopic examination in the fresh state, by teasing up parts of tis- 
sues, or by means of scrapings from the cut surface, is in most cases im- 
perative if the finer details of the cellular elements are to be fully ap- 
preciated, but sections are no less necessary in many cases if the rela- 
tions of the various constituents, and the structure with the tissue as a 
whole, are to be determined. In order to do this the method óf freez- 
ing the fresh tissue, and cutting sections with the microtome is frequent- => 
ly adopted, but it must be the general experience that such sections 
are often very unsatisfactory. They are so loose and lacking in cohe- 
sion, and the process of freezing alters the tissue so much, that they are 
difficult to manipulate and often difficult to interpret. I have occa- 
sionally met with errors in diagnosis made by incompetent observers 
from the use of such sections. — In order to obtain satisfactory results, 
the proeesses of hardening, embedding, section-cutting, staining, and 
mounting are all necessary, and these commonly extend over several 
days. If the process can be so shortened that the whole investigation 
can be completed at one sitting, then a considerable practical advant- 
age will be obtained. How often does it happen in the course of a 
pathological investigation of parts either obtained post-mortem or from 
operation that we wish to be satisfied on the spot as to the realsignific- — 
ance of some particular appearance. If the structure is put. aside to ` 
harden, there is considerable likelihood of some of the points being for- 
gotten, and, at any rate, it is not taken up with the freshness of the — — 
first examination. I believe also that for purposes of surgical diagnosis | & 
an examination made within an hour's time would often be found of E 
great value. xp 
~ The method I have now to » describe has no claim except as a prac- i 
tical working procedure. I have ti - 
. have met with a general expression ofi its usefulness. - have used it 
pene. — for more than a year, and am. perfectly satisfied that it ful- 
fils its purpose. The principles of the method are: (1) rapid harden- — 
TT esi in alcohol; (2) eutting with the microtome without | removing the Pe 
> alcohol and without freezing the tissue; (3) rapid Msn o 
|... 1. The hardening is effected by : absolute alcohol, keptata SANAA ; 
bus about. that. of the animal. body. In examining the fresh ; 
| Journ, Pathology ar and I Bacteriology; 1, Ne 4 i 1894. oa 
