214 
PATHOLQG Y. 
deed, quite bloody. The portions of pleura fituated be¬ 
neath falfe membranes, when this is the cafe, are much 
redder than in the moll acute recent inflammation, owing, 
as Laennec thinks, to a fecondary inflammation fuper- 
vening at a later period than the formation of the falfe 
membranes. The effufed fluid is generally without-taffe 
or fmell, in apute pleurify. The relative proportions be¬ 
tween the erruieci imnn anti albuminous concretions, is 
not at all fixed. Generally Speaking, the more violent 
the inflammation, the more extenfive and thick is the 
membranous exudation. In weak leuco-phlegmatic fub- 
jeds, on the contrary, we find a great quantity of lim¬ 
pid ferum, with a finall portion of thin membrane often 
floating in it. In fuch cafes, the pleurify feems to pafs 
infenfibly into hydrothorax, as we (hall fee more parti¬ 
cularly hereafter. It is an exceedingly rare cafe, M. 
Laennec obferves, to find the contiguous furfaces of the 
pleura united, without previous effufion of fluid, fince 
the abforption of the fluid is the firft ftep in the fanative 
procefs. We may therefore conclude, on finding thofe 
old adhefions of the lungs to the fides, that there exift- 
ed, in the acute flage of the difeafe, an effufed fluid ; for, 
when patients happen todie in that flage, we almoftinva¬ 
riably find an effufion. The following paflage will con¬ 
vey a clear idea of the fanative procefs in pleurify, and 
the organization of the extravaf'ated fubftances- 
It is the character of th efolje membranes produced in 
pleurify to be changed into cellular fubltance, or rather 
into a true ferous tifl'ue like that of the pleura ; and this 
is tire natural progrefs of the procefs when left quite un- 
difturbed. This change is produced in the following 
manner : The farms effufion which accompanied the 
membranous exudation is abforbed, the comprefled lung 
expands, and the falfe membranes inverting it and the 
coital pleura become united into one fubftance. By and 
by, this fubltance becomes divided into layers pretty 
thick and opaque, which are feparated by a very fmall 
portion of ferofity. About this time blood-veflels begin 
to make their appearance in it, the firft rudiments of 
which have the afped of irregular lines of blood, much 
larger than the veflels which are to take their place. 
The blood feems as if it had been forced into the fub- 
ftance of the falfe membrane by a ftrong injection ; and 
we find the correfponding portions of the pleura redder 
than elfewhere, and as it were fpotted with blood. After 
a time, the pfeudo-membranous layers become thinner 
and lefs opaque ; the lines of blood afl’ume a cylindrical 
fhape, and ramify in the manner of blood-veflels, but Hill 
preferving their augmented diameter. On minutely ex¬ 
amining thefe at this flage, we find their external coat 
conlifling of blood fcarcely yet concrete, and very red ; 
within this there is a fort of mould, or rounded fubftance, 
whitifh and fibrous, and formed evidently of concreted 
fibrine, perforated in its centre, already permeable to the 
blood, and evidently containing it. Eventually, the 
layers of the falfe membrane become quite tranfparenr, 
and nearly as thin as thofe of the ordinary cellular tifl'ue, 
and the blood-veflels refemble in every refped thofe 
which ramify on the inner furface of the pleura. It 
wants, however, the firmhefs of the natural cellular fub- 
ilance, being eafily torn in our attempts to examine it, 
and its veflels ftili retain the large diameter indicative of 
their recent formation : and it requires fome considerable 
time for them to attain the perfed charader of the ori¬ 
ginal tiflues of the body.” Thefe organizations having 
taken place, the health remains unaffeded, and the rel- 
piration, except in fome particular cafes, does not fuffer 
from their prefence. 
In Ample pleurify, we find no fign whatever of inflam¬ 
mation of the pulmonary parenchyma, even in the vici¬ 
nity of the molt inflamed portions of pleura. We find 
the fubftance of the lungs in fuch cafes more denfe and 
lefs crepitous, owing to the comprefiion of the effufed 
fluids. If the extravafation has been very great, the 
lung becomes flattened, ceafes to contain air, and con- 
4 
fequently to crepitate ; its veflels are comprefled and con¬ 
tain little blood, and the bronchia, witli the exception 
of the larger trunks, are evidently rendered fmaller. 
Sometimes, however, we obferve certain portions of the 
lungs polTefling a rednefs like that of mufcle ; and a corn- 
pad homogeneous texture, in which no trace of air-cell 
can be detected. This has been termed carnification nr 
hepatization ot the lungs. Laennec confiders it a pro- 
dud of inflammation. For fome further interefting par¬ 
ticulars as to Empyema, and the produds of chronic 
pleuritis, we refer the reader to Laennec’s work “ De 
1 ’Aufcultation mediate, &c.” 
Some authors have aflerted the exiflence of chronic 
pleurify as giving rife to Empyema, and a variety of 
morbid products within the bags of the pleura. Thefe 
fymptoms are very infidious; and we do not find them 
altogether clearly detailed in any author. A flight pain 
in the fide with dry cough (which latter brings on a 
flitch in the fide), together with a pulfe rather hard, are 
the only circumftances which occur to our recollection. 
The difeafe is feldom recognized till effufion or adhefion 
has taken place, when, according to Laennec, fome in¬ 
formation may be derived from the ufe of th s jtethofcope, 
of which inftrument we fhall prefently have occafion to 
fpeak. 
8. Emprefma carditis, inflammation of the heart: pain 
in the region of the heart, often pungent; anxiety ; 
palpitation; irregular pulfe. 
The difeafes of the heart are confefledly the mod dif¬ 
ficult to recognize in the whole range of human maladies. 
When we consider the complicated adions which the 
heart is the agent of, and the irregularities thofe actions 
are fubjeded to by alterations in the furrounding organs 
which are affociated in its movements, it will be fuffi- 
ciently obvious, that the fame difeafe of the ftrudure of 
the heart will, as it aft'eds one or other of its parts, give 
rife to various and diffimilar phenomena. To illuflrate 
this by a very Ample fad: if the capillaries of the lungs be 
obftruded, increafed propulfive power muft be exerted 
by the right ventricle ; and, the ftrudure of this portion 
obeying the general laws of all mufcular parts, its in¬ 
creafed exercife will be followed by correfpondent dimi¬ 
nution of power, and debility will enfue. To trace the 
effed of the above irregular impulle on the powers and 
fundions of the heart would lead to a wide and unde¬ 
fined department of medical fcience ; to wit, an account 
of the mode of produdion of the various morbid growths 
found in the cavities of the heart. The circumstance is 
merely mentioned to Show, that, becaufe the heart is 
compofed of four cavities, each fubjedto Similar altera¬ 
tion from different caufes, and vice verfa, we cannot but 
exped to find very anomalous fymptoms in its difeafes. 
Thus, in carditis, the moll unfat,isfadory accounts have 
been given, becaufe, till the prefent time, authors over¬ 
looked the fad, the palpable fad, that inflammation 
muff be different as it was fituated in one or another 
portion of the heart; and that in a violent degree it 
might adually be diredly oppofite in its fymptoms to its 
milder forms. 
The Symptoms ufualiy aferibed to carditis were fever, 
pain in the Situation of the heart, palpitations, an irregu¬ 
lar pulfe, cough, difficulty of breathing, and often Syn¬ 
cope. It is obvious that the fymptoms here enumerated 
are merely the common fymptoms of peripneumony, or 
pleurify, with the addition of palpitation, irregularity of 
pulfe, and fyncope, or fainting. But it is obferved by 
Senac, that thefe fymptoms are extremely uncertain ; and 
with regard to palpitation, although its prefence may lead 
us to fufped that the heart is affeded, yet it is probably 
an hypothetical opinion, fince, in that inflammation 
which arifes from wounds of the heart, palpitation doss 
not occur. (Traite du Cceur, tom. ii. chap. 7.) With 
refped to the other two fymptoms, it has been remarked, 
that the prefence of an irregular pulfe, and the occur¬ 
rence of Syncope, together with the fymptoms of pneu¬ 
monia 
