EVOLUTION OF THE STETHOSCOPE. 



489 



fossilized curiosities, the relics of former ages, on the antiquated 

 shelves of some very old medical practitioner. The stethoscope, as 

 you know, was invented by Laennec. He relates how in the year 

 1816 he happened to recollect a well-known fact in acoustics of solid 

 bodies conveying sound, and he goes on to say : " Immediately on 

 this suggestion I rolled a quire of paper into a kind of cylinder and 

 applied one end of it to the region of the heart and the other to my 

 ear, and was not a little surprised and pleased to find that I could 

 thereby perceive the action of the heart in a manner much more clear 

 than by the application of the ear. . . . The first instrument which I 

 used was a cylinder of paper formed of three quires completely rolled 

 together and kept in shape by paste." Laennec then goes on to de- 

 scribe how he copied this roll of paper in wood, metals, glass, and 

 other substances, and finally he says : " In consequence of these vari- 

 ous experiments I now employ a cylinder of wood an inch and a half 

 in diameter and a foot long, perforated longitudinally by a bore three 

 lines wide and hollowed out into a funnel-shape to the depth of an 

 inch and a half at one of its extremities. It is divided into two por- 

 tions, partly for the convenience of carriage and partly to permit its 

 being used of half the usual length. The instrument in this form 

 that is, with the funnel-shaped extremity is used in exploring the 

 respiration and rattle ; when applied to the exploration of the heart 

 and the voice, it is converted into a simple tube with thick sides, by 

 inserting into its excavated extremity a stopper or plug traversed by 

 a small aperture and accurately adjusted to the excavation. This in- 

 strument I have denominated the stethoscope? 



Fig. 1 represents Laennec's roll of paper, and Figs. 2 and 3 the 

 copy of this in wood as he describes. The latter figure is drawn from 

 an instrument kindly given me by Dr. Galton, of Norwood, being the 

 stethoscope long used by his father. It does not separate into two 



Fig. 3. 



pieces, but contains the plug which can be removed so as to leave the 

 end hollow. Fig. 4 is the same instrument with the sides cut out to 

 make it lighter and more elegant, the ear-piece being the same as 

 before, and the mouth also hollowed out. This was the stethoscope 

 used and recommended by the late Dr. Hughes. By making the in- 



