Nevertheless, as the mass of the lung has retained its trans-
parency, each of these foci gives, on radioscopic examina-
tion, a definite shadow which stands out against the clear
background of the parenchyma,. The radioscopic image of



108 RADIO-DIAGNOSIS: LUNGS

this form of broncho-pneumonia is thus made up of a series
of distinct shadows, more or less confluent, and separated
from one another by clear spaces. It has exactly the ap-
pearance of certain forms of chronic tuberculosis with dis-
seminated foci which, however, are nothing else than foci
of tuberculous broncho-pneumonia. The limg shows a
mottled appearance.
This appearance is clearly shown in Radiograph 16 — a
series of diffuse, definite shadows, much more confluent at
the right towards the base and the region of the hilus, much
more questionable at the left. This was a case of a lobular
broncho-pneimionia, verified by autopsy, in which the con-
fluence of the diseased centers was perfectly visible on the
plate. It was a common broncho-pneumonia, following a
chronic bronchial infection, and not a case of tuberculosis.
The clinical development, the absence of bacilli in the spu-
tum, and the absence of tuberculin reaction indicated that
tuberculosis was not a cause. Autopsy and histological
examination of the lung confirmed this. It is evident then
that simple lobular broncho-pneumonia may give a radio-
scopic picture analogous to that of certain forms of chronic
tuberculosis with disseminated foci and that it is the clinical
side alone which informs us of the nature of the pulmonary
process.
Abscess of the Lung. — The metastatic or pyemic ab-
scess following infectious diseases, or sm-gical pyemas will
not be dealt with: nor migratory or secondary abscess fol-
lowing abscess of the liver, colon, or mediastinum. Pneu-
monic abscess only will be discussed.
