SPORADIC PNEUMONIA AND CONTAGIOUS PLEURO-PNEUMONIA. 531 
contact of the air, but preserves the same size when removed 
from its cavity. It is very heavy, and keeps the impression of 
the finger, except at the topmost part, where it has yet a certain 
elasticity. 
The pleura, when sound, shows through its transparency the 
coloration of the pulmonary tissue, rutilant red, then strong 
purple in the superior part of the lung, growing gradually to a 
red brick color in the middle, to become of a dirty red towards 
the lower part of the organ. 
Upon this coloration is seen a network of various tints, divid¬ 
ing the surface of the lobe in a great number of irregular poly- 
edrical surfaces. This network, formed by the interlobular 
sections under the pleura, is not seen in the healthy tissue. Of 
a blackish purple in the superior congested portion, it becomes of 
a yellowish white in the lower parts of the lungs. 
Upon a transversal section of a lobe are found, ordinarily, 
lesions which indicate that the inflammatory process has started 
from the lower portion of the organ to spread by degrees towards 
the superior, in such a way that the density, the coloration, the 
texture of the parenchym of the organ varies from one region to 
the other, according to the length of standing of the inflamma¬ 
tion. 
The parenchym of the upper portion, only hyperhemic, lias 
the same cellular texture and elasticity; it is difficult to cut,floats 
in water, and towards the superior border is evidently em¬ 
physematous. 
In the middle of the lung the color is of a darker red, the 
tissue heavier, easier to tear, less elastic, aud exhibits the first 
degree of hepatization. And then in the lower region the colora¬ 
tion has passed from the brick red to a dirty tint, comparable to 
that of boiled meat. There the tissue is very heavy, very easily 
tore, entirely hepatized, its cut is even, and when torn it is evi¬ 
dently granular. 
• On that section is seen again the subpleural interlobular 
arborization, dividing the parenchym in as many irregular poly- 
edrical surfaces as there are of lobes. These divisions, emphy¬ 
sematous towards the superior border of the lobe, are not very 
