194 Sir Everard Home on the coagulation by heat 
EXPLANATION OF THE PLATES. 
Plate III. An anterior view of the aneurismal sac. 
Fig. 1. A small portion of the aorta ; the division into the 
two iliac arteries. The sub-division into the external and 
internal branches. The external iliac artery traced along its 
course to the opening into the sac. The upper part of the 
femoral artery slit open, from the lower orifice in the sac to 
the part where it became obliterated by the coming away of 
the ligature. 
Fig. 2. The lower part of the aorta slit open; also the 
common trunk of the iliac artery, to show that the internal 
membranes of both have begun to ossify. The figures are 
of the natural size. 
Plate IV. An internal view of the aneurismal sac. 
Fig. l . The aorta and external iliac passing on the outside of 
the aneurismal sac. The lamina of the coagulum first formed, 
and resembling those met with in other aneurismal tumours. 
The opening into the arterial trunk from the coats having 
given way for the space of one inch, exposing the upper and 
lower orifice of the artery ; and showing that the sac adhered 
to the artery even higher than the going off of the internal 
iliac. 
Fig. 2. A small portion of the blood coagulated by the 
heated needle, which has a foliated structure, the leaves thin, 
compact, and connected together by thread-like filaments. 
Both these figures of the natural size. 
Fig. 3. One of these leaves magnified ten diameters; its 
surface studded over with nodules of coagulable lymph, like 
so many drops of melted wax. 
