CHANGES THE LUNGS UNDERGO IN PNEUMONIA. 736 
pleural disease, to which I would for a moment call the atten¬ 
tion of practitioners who seem to be at variance in their opinions 
as to the duration of time required for such changes to take place. 
It is hardly necessary for me to premise, that in the examina¬ 
tion of lung in search of the cause of dissolution, distinctions are 
to be made, no less in point of the duration of time in which 
such transformations may occur than as to their nature, between 
congestion , reddening or discolourization, softening , condensa¬ 
tion , hepatization, tubercularization, 8$c. It is not my intention, 
however, within the limited bounds to which this paper must be 
confined, to enter into any detailed pathological accounts of these 
several pulmonary changes; but simply to make a few ob¬ 
servations touching the more remote of these consequences, not 
so much as to their nature as to the period of time required for 
their formation. 
In congestion—a state distinct from that of inflammation— 
the pulmonary trunks and their branches are gorged with blood 
to that extent that the lung itself has the appearance of a mass 
of coagulated blood, the colour of which has often approached 
so near black as to be pronounced mortified. Whereas, in 
pneumonia, it is in the capillary vessels of the parenchymatous 
substance that engorgement takes place, with more or less 
reddening, which has no sooner reached a certain height than 
stagnation results, and there ensues after a time a mingling of 
the red particles with the serum of the blood, with more or less 
solution of th'e latter; to this exosmosis follows, and the morbid 
condition known by the name of sanguineous infiltration is the 
result. Next comes blocking-up of the already compressed 
air-cells by lymph effused into them from the capillaries, gra¬ 
dually producing solidity of them and all around them, until 
the lung has become converted into a solid, though rather 
soft than firm, mass of substance, destitute of all porosity save 
what it retains from being traversed by the unclosed large 
ramifications of the bronchi and pulmonary vessels. This is 
* the condition of lung we call—from its resemblance to liver— 
hepatization , which being interpreted means red softening. 
The augmentation of weight, as well as change of structure, 
occasioned in the lung so affected, is almost beyond the con¬ 
ception of any one save him who has handled viscera of the 
kind. This solidity, however, in time gives way to further 
softening and further changes. It turns speckled, altered in 
colour in circular patches, becomes what is called granulated . 
This constitutes the tubercle resulting from infiltration, which 
from the greyish or reddish or yellowish aspect it puts on, 
gives the cut surface of the lung the marbled appearance so 
characteristic of the changes still to follow. For now sup- 
