PRIZE ESSAY. 
347 
Changes in the Lungs .—The situation of the disease of the 
lung is generally shown by the lesions, already mentioned, of the 
pleura. But if this is absent, the pleura not being affected, the 
portion of diseased lung tissue can still be easily recognized as a 
hard, heavy, airless, discolored mass, standing out boldly from 
the neighboring normally collapsed lung tissue, which is light, 
soft and elastic. 
The extent to which the organs may be affected varies great¬ 
ly ; it may be a nodule the size of a man’s fist, or, in a long stand¬ 
ing case, the whole of one lung (more often the right), or the 
greater part of both, may seem to be involved. By inflation, the 
small remaining healthy portion may be brought into view. Even 
in an inflated lung, however, the diseased stand out above the 
healthy portions, being considerably increased in size, from the 
hyperplasia in the interlobular spaces. 
If, now, a section be made through the affected part, cutting 
from the surface toward the root of the lung, we find the diseased 
part wedge-shag)e, the point .towards the root, the broad part to 
the pleural surface. This is not so well seen in the advanced 
cases, but is exceedingly characteristic in the earlier stages. The 
line of demarcation in these cases always corresponds to the in¬ 
terlobular spaces. These sharp lines of demarcation, not only 
between the healthy and diseased structure, but also between the 
several territories affected with the various degrees of morbid 
change (which are so different in color), are among the most 
obvious characters of the anatomical appearances. 
Perhaps the most striking appearance seen on the cut surface 
is the net-work of pale yellow lines which is distributed over it. 
The lines forming this network are, on an average, about ^ of an 
inch in diameter. They cross each other so as to map ont the 
surface into a number of polygonal areas, about one-half or three- 
quarters of an inch in diameter. These areas are found to corres¬ 
pond to the lobules, and the lines are formed by the exudate in¬ 
to the interlobular connective tissue. These pale lines resemble, 
in a cut lung, the veins in marble, hence that name has been 
given. This marbling is considered (by some) to be the great 
diagnostic character of this disease.* 
* It is but proper to state that, although Professor Yeo aud others hold the 
opinion stated above, Professor Williams and others dissent entirely from it. 
