mmentators," writes Corvisart, "and I might easily have elevated
myself to the rank of an author if I had elaborated anew the doctrine
of Avenbrugger and published an independent work on percussion. In this
way, however, I should have sacrificed the name of Avenbrugger to my own
vanity, a thing which I am unwilling to do. It is he, and the beautiful
invention which of right belongs to him, that I desire to recall to
life."(1)

By this time a reaction had set in against the metaphysical methods in
medicine that had previously been so alluring; the scientific spirit of
the time was making itself felt in medical practice; and this, combined
with Corvisart's fame, brought the method of percussion into immediate
and well-deserved popularity. Thus was laid the foundation for
the method of so-called physical diagnosis, which is one of the
corner-stones of modern medicine.

The method of physical diagnosis as practised in our day was by no means
completed, however, with the work of Corvisart. Percussion alone tells
much less than half the story that may be elicited from the organs of
the chest by proper interrogation. The remainder of the story can
only be learned by applying the ear itself to the chest, directly or
indirectly. Simple as this seems, no one thought of practising it for
some years after Corvisart had shown the value of percussion.

Then, in 1815, another Paris physician, Rene Theophile Hyacinthe
Laennec, discovered, almost by accident, that the sound of the
heart-beat could be heard surprisingly through a cylinder of paper held
to the ear and against the patient's chest. Acting on the hint thus
received, Laennec substituted a hollow cylinder of wood for the paper,
and found himself provided with an instrument through which not merely
heart sounds but murmurs of the lungs in respiration could be heard with
almost startling distinctness.

The possibility of associating the varying chest sounds with diseased
conditions of the organs within appealed to the fertile mind of Laennec
as opening new vistas in therapeutics, which he determined to enter to
the fullest extent practicable. His connection with the hospitals of
Paris gave him full opportunity in this direction, and his labors of
the next few years served not merely to establish the value of the new
method as an aid to diagnosis, but laid the foundation also for the
science of morbid anatomy. In 1819 Laennec published the results of his
labors in a work call