Though we often meet with typical forms of _bronchitis_, _pneumonia_ and
_pleurisy_, it is much more common to find them combined more or less
with each other. Thus combined inflammation of the bronchial tubes and
pulmonary substance is frequent; inflammation affecting both the lung
and its investing pleural membrane is no less common; and cases are seen
in which all three structures are involved. These conditions are to be
recognized by the presence of the symptoms of both the coexisting
maladies but particularly by the indications furnished by touch,
auscultation and percussion. The predominance of one disease over
another will decide the nature of the treatment which must be adapted to
the peculiar character of each case whether _mainly bronchitic_,
_pneumonic_, or _pleuritic_. It is these mixed cases that test the
ability and judgment of the practitioner as he must carefully
individualize each case, ascertain the different parts affected, the
grade of the inflammatory action, the nature of the attendant fever, the
presence or absence of epizootic influence, etc., and having all these
conditions in view must apply remedial measures accordingly.
It must be evident that particular directions cannot be supplied for all
of these cases. General principles only can be inculcated and their
adaptation to the varied phases of different cases left to the judgment
of the student.