38 



foot in a minute. This I believe to be a very close approximation to 

 the pow^er of the heart ; but, inasmuch as it was not obtained by direct, 

 but by indirect reasoning, I thought it desirable to proceed to verify it 

 by another process; and, in the verification of this coefficient of muscu- 

 lar force of the heart by a second process, I made use of a very interest- 

 ing phenomenon. This phenomenon w^as observed by the celebrated 

 Dr. Wollaston, M^ho wrote a paper upon it, which is published in the 

 Philosophical Transactions for 1809, Dr. Wollaston was the first 

 person who noticed that, when our muscles are contracted, they give 

 out a deep musical note. If any of you wish to repeat the experiment 

 for yourselves, and satisfy yourselves about it, I will inform you of the 

 simplest modes of doing so. If you go into a room by yourself in per- 

 fect silence, place your elbows firmly on the table, and close your ears 

 lightly with the forefingers, clenching the muscles of the forearm, you 

 will hear immediately a deep musical hum, which never can be con- 

 founded with any other sound you heard before. Dr. Wollaston com- 

 pares it most accurately to the rum.bling sovmd produced by the noise of 

 cabs driving over the pavement in the silence of the night. Or if you 

 awaken at night and clench your teeth so as to call the masseter muscles 

 into action, you will hear with the ear that lies next the pillow, which 

 acts as a sounding board, this deep hum, which you can destroy by 

 ceasing to clench your teeth, and renew at pleasure. You can, there- 

 fore, very soon satisfy yourself that the act of contracting the muscles 

 is accompanied by some phenomenon that takes place in rapid succes- 

 sion, comparable with the motions that produce a musical note. My 

 attention was first directed to this curious subject in a remarkable way ; 

 and it so happened that a young physician of Marseilles in a similar 

 way was attracted to the study of this curious phenomenon. Dr. Col- 

 longues of Marseilles had charge of the cholera hospital in that town ; 

 and he observed, in studying some of the cases which had died, a re- 

 markable fact. Dr. Collongues in Marseilles, and myself in Dublin, 

 pursued our studies each without knowing that the other was engaged 

 in them. A patient in cholera has his temperature much lower than 

 the natural heat of the blood, which is 98 deg. ; and it is well known to 

 physicians that in diseases like fever, if the blood-heat rise some seven 

 or eight degrees above that, the patient will die. It is equally well 

 known that in diseases like cholera, if the blood-heat fall more than 

 seven or eight degrees below 98, the patient will die. Therefore it is 

 a strange fact that, when you examine the body of a person who has 

 died of cholera, when you put your hand upon the body, it is warm ; 

 the temperature, which was 90 deg. before death, rises after death to 

 103 or 104 deg., just as if the person were still living and in the height 

 of a violent fever. This is accompanied also with spontaneous move- 

 ments occasionally of the limbs, which cause great alarm to persons 



