556 
MR. BISHOP ON THE PHYSIOLOGY 
struck M. Biot as one of the circumstances which in his opinion prove their mode 
of vibration to be unlike that of strings. He asks, “ Oil pourroit-on trouver la place 
necessaire pour donner a cette corde la longueur qu’exigent les sons les plus graves ?” 
Subjects of experiment. 
No. of experiments. 
1 . 
2. 
3. 
4. 
5. 
6. 
Male in a state of repose 
0*7087 
0*63 
0*63 
0*83 
0*748 
0*748 
Male in the state of greatest tension... 
0*83 
0*83 
0*984 
1*0236 
0*9055 
0*9055 
Female in a state of repose 
0*47244 
0*47244 
0*551 
Boy of 14 ii 
0*414 
repose. 
Female in the state of greatest tension 
0*63 
0*59 
0*63 
Boy of 14 g 
0*571 
reatest tensi 
on. 
Mean length in male 
In repose. 
0*72834 
Greatest ten 
0*912070 
sion. 
Mean length in female 
0*49868 
0*61679 
The author is acquainted with some bass singers who can produce the note C which 
results from sixty-four musical vibrations. Let us now investigate this phenomenon 
more closely, and endeavour to explain how such grave tones are produced by such 
extremely short membranes. Muller has contrived several ingenious pieces of me- 
chanism, seen in Plates XXXI. and XXXII., by means of which he was enabled to 
estimate the amount of tension, lateral compression, and atmospheric pressure on the 
vocal cords, during the production of sound. In order to find the variations in the 
amount of condensation of air in the vocal organs in the production of sounds differing 
in pitch and intensity, the apparatus was furnished with a manometer, Plate XXXI. 
fig. 3. v. From that portion of the experiment which was confined to the investiga- 
tion of the effects produced by tension of the vocal, compared with that of musical 
cords, he obtained results which are comprised in the following table. 
No. of experiments. 
Weights en 
lploved. 
4 loths*. 
16 loths. 
64 loths. 
1 
C 1 
A 1 
2 
C'S 
B> 
A% A 2 
3 
G‘# 
c*fc 
O 
4 
A 1 
D 2 
O 
5 
A# 
Ff 
G 2 
6 
A# 
G'$ 
G3 
7 
D 1 
C 2 
A 2 
8 
D '# 
B> 
A 2 
9 
G 
G l 
G 2 both octaves imperfect. 
The notes of the different octaves from C to C are distinguished in the above 
* A loth = 225*5531 gis. English. 
