THE STORY OF NINETEENTH-CENTURY SCIENCE 



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 estab- 

 lish 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 called Traite cT Auscultation M^diate^ 

 a work which forms one of the landmarks of scientific 

 medicine. By mediate auscultation is meant of course 

 the interrogation of the chest with the aid of the little 



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