SOCIETY MEETINGS. 
371 
torpid periplierous organs, vegetating, so to say, imperfectly under the embar¬ 
rassment of continued pressure. 
( b) Mechanical hyperaemia frequently becomes absolute stasis as seen in in¬ 
carcerated, strangulated organs, and as a result of the plugging of the returning 
vessels in the lower extremities. 
(c) Every inflammatory stasis may degenerate into absolute stasis, more 
particularly those hypostatic and asthenic inflammations which occur in organs 
already diseased, paralyzed or depressed by violent external influences, such as 
concussion, contusion, heat or cold. An inflammation consequent upon influences 
directly or indirectly debilitating, may acquire during its progress, a tendency to 
absolute stasis. 
In absolute stasis, the blood undergoes gangrenous decomposition. Hence 
the blood is the portion originally necrosed and dissolved. It exudes in a state of 
gangrenous ichor through the walls of the blood vessels, causing the same gan¬ 
grenous decomposition in these and in the surrounding tissues. This event gives 
rise to the most ordinary and most developed form of moist gangrene. The pro¬ 
gress of this gangrene is more or less acute, the gangrenous dissolution of tissues 
being marked by the rapidity of its course. 
Second .—Gangrene is determined by failure in supply of blood. 
(a) In impermeability of large arteries,—high degree of carrctation, and 
complete obstruction consequent upon arteritis and ossification. 
Here gangrene takes the form of dry, black, nummifying gangrene. 
(&) As a result of compression ahd tension of a part; as in strangulated 
hernia. 
(c) As a result of local destruction of blood vessels, the denudation of parts 
of attaching and blood supplying textures, bones for example, of their external 
and internal periosteum, the common integuments of their supporting areolar 
tissue. The peritoneum of its subjacent layers; isolation of the pleura-pul- 
monalis over cavities of the lung. This gangrene appears as a white or yellowish 
white slough. 
(d) Extensive impermeability of the capillaries and minute vessels when 
plugged with coagula or compressed by surrounding exudates. In the last men¬ 
tioned case, the gangrene is dependent upon inflammation. To this kind of 
gangrene textures poor in blood vessels, such as compact bones, collasities, etc., 
are especially obnoxious. The color of the necrosed textures is commonly of a 
yellow or yellowish green hue. 
Third .—'The gangrene is the expression of the localization of an anomaly in 
the blood-crase, either directly engrafted by contagion or developed out of other 
erases; a putrid decomposition of the circulating fluid. Blood so poisoned, 
especially if brought into stasis or into coagulation, possesses, in common with 
the exudates thrown out by it, an inherent tendency to gangrenous dissolution. 
It has already been stated that several varieties of gangrene have been recog¬ 
nized— 
1. —Gangrene developed out of an internal cause is distinguished, by the 
designation of primary grangrene, from that arising from an external cause. 
2. —Hot, acute inflammatory gangrene.—True gangrene, in the manner 
which inflammation leads to gangrene, is sufficiently clear from the foregoing. 
