116 
tained the namie of the false or adventitious 
membrane of croup. This substance is of a 
pale yellow colour, viscid and tenacious ; more 
generally found in the larynx than the trachea ; 
seldom occupying the entire circumference of 
the tube ; unorganized ; incapable of becoming 
the medium of union between opposing sur- 
faces, and with a strong disposition to separate 
from the surface on which it was originally 
formed. It usually commences in the larynx, 
and travels downwards along the trachea; more 
rarely it seems to beyin in the ramifications of 
the bronchial cells; and again, still more sel- 
dom is the entire of the mucous membrane 
attacked at once, and the adventitious mem- 
brane thrown out over its whole extent. Con- 
sidered as a pathological production, this false 
membrane of croup presents some curious and 
interesting subjects for observation, for although 
so generally met with that by some it has been 
regarded as the essential characteristic of the 
disease, yet perhaps it is not invariably or ne- 
cessarily so; at least I have seen cases so far 
resembling croup in all their stages, that they 
could not be distinguished from it during life, 
in which dissection subsequently shewed the 
mucous membrane swollen, and soft, and 
pulpy, with copious submucous effusion, yet 
without the formation of a single flake of 
lymph. Possibly in the few cases of this de- 
scription that came under my observation, the 
disease had proceeded with a rapidity which 
roved fatal before the membrane had time to 
ave been formed. Again, it is the only* 
instance of lymph being produced ona mucous 
surface as the result of active acute inflamma- 
tion. In chronic affections membranous layers 
of lymph are often formed, and in different 
situations, as in the bronchial cells and the 
mucous coat of the intestines, but the acute 
produces it alone in the structures that are the 
seat of croup. And lastly, it appears that this 
effect of inflammation is restricted to patients 
under twelve years of age. Mr. Ryland, in his 
excellent treatise on the larynx, has published 
atable from Bricheteau, by which it is shewn 
from the experience of fourteen distinguished 
authors, that croup “has never occurred at a 
later age than twelve years, and very rarely at 
that age.” My friend, Dr. W. Stokes, con- 
siders the cases published as examples of croup 
occurring in the adult as not being inflamma- 
tory croup at all, but analogous to the diphthe- 
rite of Bretonneau, which will be shewn to be 
avery different disease indeed. 
Such is the pathological condition of the 
rts in the second stage of croup—a condition 
indicated by the increased difficulty of breath- 
ing—the pale and swollen countenance—the 
straining eye—the dilated nostril and the purple 
lip; by the occasional expectoration off some 
portions of the false membrane; and (as hap- 
pens in every affection of the larynx) by severe 
and protracted spasms of the glottis. If the 
patient still continues unrelieved, the third and 
* For an apparent exception to this rule, see a 
case published in the Dub. Journ. of Med, Science, 
September 1838, No. 40, vol. 14. 
ABNORMAL ANATOMY OF THE LARYNX. 
last stage supervenes. The child still breath 
with difficulty, but with increasing lang 
its countenance is pale; its lip b 
there are generally convulsions, in — 
which the fatal event may take place; 01 
he sinks gradually, exhausted and worn 
and dies comatose. And we are to hk 
the actual and immediate cause of des 
the larynx but to the lungs and br 
matter how much the membrane may 
swollen, or how extensively the false mi 
brane may have been formed, the rima 1s 
completely closed, and the patient dies, 
because there is an absolute insufficiency of 
to provide for the arterialization of the b 
but because some change has taken plat 
the organ by which this most important 
tion is performed. When the thorax is op 
the lung does not collapse under the infla 
of atmospheric pressure : when the lung is 
into, it is found to be loaded with dark b 
and with frothy serum, the effusion of ¥ 
latter is often so abundant as nearly to fil 
trachea. The brain, if examined, is ft 
congested, and not unfrequently is there 
effusion of serous fluid into its ventricles. 
The acute inflammation of the mucous 0 
brane of the larynx bears no resemblan 
the adult to that in the child, excepting on 
the agonizing difficulty of respiration a1 
fatality of the result, but the pathological 
ditions are different, and therefore is the di 
in the adult far more manageable. I 
scarcely conceive, much less describe the 
istence of acute laryngitis to any dange 
extent in the membrane alone withe 
participation of the submucous tissue, in 5 
the perilous tumefaction is generally, | ‘no 
ways, seated; I shall, therefore, as I has 
therto done, consider this affection in e d 
tion with its principal pathological result— 
formation of an cedematous effusion. — 
Mucous membranes in every situation $€ 
to be connected to the adjacent tissues by 
species of cellular membrane termed reticul 
as a provision that the courses of the can 
which they form so important a part shoul 
be impeded by any accumulation of fat 
this reticular membrane is more or les 
according to the nature and consistence ¢ 
subjacent structure. Where mucous 
brane is attached to bone, the nature of 
connecting medium is so short and close, 
in many instances it is scarcely obs 
and the membrane, in addition to its 
tions, appears to perform that of a periost 
whilst in other situations, as in the intest 
is so lax as to allow the organ to become 
tended to an almost unlimited extent. 
usual effect of inflammation on this ret 
tissue is an effusion of a serous fluid wit 
cells, and the production of edema; bi 
is of little consequence where the | 
dense and close, and perhaps of sti 
where the organ is widely distensib 
larynx, however, presents an organ of 
character—the mucous membrane is 
tached to muscle and to ligament, 
ee 
