— 13 — 
A satisfactory microscopical examination of organs in such a condition is not 
possible, not only on account of the l)rittleness of the tissues, but also because the micro- 
scopic structure is obscured by an opaque, dark brown colouring matter with wiiich 
the tissues are saturated. Further, the large amount of the closely adherent «packing» 
e. g. mud, charcoal, sand and sawdust increases the difficulty. 
The objects to be attained were: 1°, to soften the tissues in order to render tliem 
less brittle, 2", to remove the colouring matter, and 3°, to bring back consistency 
sufficient for histological examination. 
Microscopical sections liad to be prepared, as except in the case of muscular fibres, 
all other method such as teasing, etc., proved useless for the reasons already stated. 
I need not enumerate all the reagents I employed together and seriatim. The 
main difficulty was that reagents such as alkalies, neutral, alkaline and acid salts, 
mineral and organic acids, glycerine, formol, acetone, alcohol, chloroform, ether, etc., 
whether employed together or alone or in solutions of different concentrations, either 
softened tlie tissues too much or not enough, and the invariable result was failure. 
After many attemps the following stock solution proved most useful : 
Alcohol 30 CCS. 
Water 50 „ 
5 % Carbonate of soda solution 20 „ 
In some cases instead of water and alcohol a 1 " o solution of formol was used. 
Although this solution generally gives good results, yet the details of the process 
must often be altered. The time during which the tissues remain in this solution, and 
the percentage of alcohol and carbonate of soda require modifying according to the size 
and consistency of the tissue to be studied. The harder and larger the tissue, the more 
carbonate of soda required, and the longer the time during which the tissue must 
remain in the liquid. The process thèrefore is delicate, empirical, and requires constant 
watching. On the whole it is better to soak small pieces (3 to 5 millimetres) in dilute 
solutions of carbonate of soda, rather than larger ones in stronger solutions. 
Within two minutes of placing the tissue in the softening solution, a brownish- 
yellow colouring material begins to dissolve out. This does not diffuse readily throughout 
the fluid, but falls to the bottom of the beaker ; so that for hours and days even, the 
lower layer of fluid resembles a strong solution of iodine, the supernatant liquid re- 
maining almost colourless. This brown colouring matter is thus extracted not only from 
organs which had been removed from the body during the process of embalming and 
then replaced, but also from muscles, bloodvessels etc., which had been left in situ; 
and even, though in lesser quantity, from the heart. The muscles appear to contain a 
great deal of it. During this process, a certain quantity of mud, sand, sawdust, etc., 
drops off the tissue and can then be mechanically removed. 
The tissues, especially the internal organs, after remaining in the fluid for a few 
hours, sometimes become so soft that the slightest movement of the vessel may entirely 
Diffi rid ties 
of Iiistoloffical 
examination. 
Composition 
of softening 
solution. 
Meth od 
of preparing 
mummified 
tissues for 
histological 
examination. 
