Proceeding of Philosophical Societies. [July,^ 



but they would then be in a state very contrary to that in which 

 they are found when an aneurism is formed ; for then, by forcing 

 out the blood with too great violence into the pulmonary arte- 

 ries and the aorta, aneurisms might be produced in those parts, 

 but not in the cavity of the heart, from whence the blood 

 proceeded. 



M. Portal, from these observations, concludes in favour of the 

 opinion of many celebrated physicians, that anmirisms are always 

 passive in respect to the force of the sides of the heart ; absolute 

 or relative to the action of the blood against the same sides ; 

 and that the indications of aneurisms given by these skilful 

 practitioners are quite certain, and their practice, relative to 

 blood letting, is the best established, and the most efficacious. 



Baron Percy has communicated to the Academy some curious 

 historical researches w^on mericism, a kind of disgusting indispo- 

 sition, consisting in brmging ap into the mouth the half digested 

 food, to swallow it a second time. It is a sort of rumination that 

 has caused those physicians who have spoken of it to advance 

 very extravagant opinions, all of which M. Percy reduces to 

 their proper value. 



Several diseases of the chest, by altering the proportion between 

 the hoUow and occupied places in that cavity, or by diminish- 

 ing entirely or partially the faculty that the lungs possess of 

 expanding or contracting, produce a change of sound from the 

 sides of the chest when they are struck — a change which yields, 

 in certain cases, some useful indications respecting the causes ' 

 which produce it. 



From this has arisen the art of discovering the affections oT 

 the chest by percussion, concerning which, Avenbrugger, a 

 physician of Vienna, published a treatise, which has been tran- 

 slated and extended by Mr. Corvissart. But much more deh- 

 cate observations may be made, either by bringing the ear nearer, 

 or by using instruments ; this kind of observations constitutes 

 the art of exploring the diseases of the thorax by means of aus- 

 cultation. 



M. Laennec, a physician of Paris, has presented to the Aca- 

 demy an essay upon this subject, in which he explains a method 

 of his own. Sometimes he uses a solid cylinder, sometimes a 

 tube with thick sides, and sometimes a tube hollowed out Kke a 

 funnel : he applies one end of these instruments to different parts 

 of the thorax, and brings his ear near the other end. 



The tube with thick sides, or cylinder pierced along its axis 

 with a narrow aperture, being applied to the ch^st of a person, 

 who is speaking Or singing, there is heard, if the person is in 

 good health, no more than a sort of trembling noise more or less 

 distinct ; but if an ulcer exists in the lungs, a very singular 

 phenomenon happens. The voice of the sick person can no 

 longer be heard by the ear at liberty ; the whole of the sound 

 passes along the aperture of the cylinder to the observer. Com- 



