84 ON SPONTANEOUS GANGRENE FROM ARTERITIS, ETC. 
If now the limb be left for several hours, the skin having been carefully replaced 
so as to prevent evaporation, the clear colourless upper layer will be found 
to occupy nearly two-thirds of the length of the portion of vein, and to be sharply 
defined from the black lower layer which contains all the red corpuscles. If 
now the upper part be punctured, the clear liquor sanguinis will flow out, and 
coagulate upon any object held to receive it.’ 
Some of the observations above described will have a bearing upon medico- 
legal inquiries, showing, as they do, that not only ecchymosis, which some have 
denied, but even inflammation may be developed post mortem, provided that 
the return of blood by the veins is in some way prevented. 
There are other bearings, both upon pathology and practice, to which 
I cannot even allude on the present occasion; but I thought it best to place 
the facts at once before my professional brethren, confident that they will 
receive from them all the attention that they may deserve. 
In conclusion, I have to express my thanks to my friend, Mr. Craig, for 
the kind and able assistance which he has afforded me throughout this investiga- 
tion, and also to my friends, Drs. Gourlay and Hill, who have on several occasions 
lent me most valuable aid. 
* Post mortem congestions simulating inflammation are, I suspect, due to this gravitation of the 
red corpuscles of the still fluid blood into the vessels of dependent parts. 
