102 
ON ABSCESS. 
of the abscess and the time it has existed, and the more perfect the 
solution of the tissues and maturation of the abscess, the more it 
approaches the circumference of the inflamed part. In those situa- 
tions where the cellular membrane is plentiful, the tissue in which 
abscesses form, this cystic sac arrives at a high degree of resist- 
ance and firmness, whilst in organs or parts but sparely possessing 
cellular tissue, as the brain, &c., it exists a long time in the con- 
dition of a reddened pellicle, with difficulty to be distinguished 
from the healthy tissue to which it adheres. The firm dense cyst 
is not commonly found in the acute inflammatory abscess, its 
formation being too quick to allow of much condensation and thick- 
ening, as is generally produced by slow inflammatory action. The 
cystic membrane seems to possess other functions than a boundary 
wall to the cavity, preventing the defilement of the surrounding 
tissues by the purulent fluid contained in them; exhalation and 
absorption is proceeding in its surface, the inclosed liquid is inces- 
santly renewed, its property qualified, and decomposition pre- 
vented. The influence of life is not entirely apart from it, but the 
vitality of the surrounding textures is in some degree extended to 
it; indeed, all fluid collections in organized parts participate in 
the vitality of the adjoining tissues, though in a weak and obscure 
degree. The fluid contained in abscesses is augmented or lessened, 
grows thicker or more fluid, or is occasionally changed by sub- 
stances absorbed or injected into the circulation, through the me- 
dium of this vital envelope. It is through the connexion of this 
membrane, by an intimate sympathy with the principal centres of 
life, that the stimulating of some of the important viscera acts upon 
them in so marked a degree, and the application of remedies to 
these organs, skilfully made, frequently assists in promoting the 
absorption of the liquid contained within them. 
In the chronic form of abscesses the progress of inflammation is 
slower, and the symptoms of irritation, both antecedent and existent 
with the disease, are proportionally less. We occasionally observe 
fluctuating tumours, superficial and deeper seated, and varying in 
size, unaccompanied by much apparent increase of heat or signs of 
pain, either preceding or succeeding their formation. Collections 
of matter in abscess is of the slow and indolent kind, originating 
commonly from a continued low degree of irritation, or from a 
repetition of so low a grade of excitation as barely to move or 
influence the sensibility of the part. They take place in subjects or 
parts possessing a feeble vital resistance and deficient restorative 
power — unlike the abscesses I have been previously describing, 
which proceed from an inflammatory action of a more or less acute 
character, the effect of active stimulation, and affecting the system 
in an active manner, in a greater or less degree. Sometimes the 
irritation of the part affected is of so low a grade as scarcely to 
