1885] . 
The Inter-Relations of the Senses. 287 
colours distinctly. Two neighbouring notes seem to him 
almost identical. The highest notes are, for him, ac- 
companied with brilliant colours, and the low notes ’with 
sombre colours.— (See “ Annales d’Oculistique,” Nov. and 
Dec., 1882.) 
In a perfect chord the three notes, if they vibrate 
absolutely together, produce the impression of one and the 
same colour, resulting from the three harmonious notes. 
The choid of fa major produces a yellow colour and that of 
la minoi a violet. In a discord some of the notes seem to 
detach themselves with their especial colour to a small 
distance from the other colours. 
The key does not seem to have any action on the pro- 
duction of the chromatic sensation. We find no relation 
between the colours called up by major keys and by the cor- 
responding minor keys. If we transpose a piece of music 
from one key to another, the tint is more brilliant if we pass 
to higher tones, but more sombre in the reverse case. 
One and the same piece of music played upon different 
instruments presents different colours. Thus the Breton 
air, Au Hollaika, played on a tenor saxophone or a har- 
monium is yellow ; it is red on a clarionet and blue on a 
piano. 
Every noise (as distinguished from musical sounds) pro- 
duces a chromatic perception, but the colours are sombre, 
generally grey. The more intense the sound, the more the 
colour sensation is accentuated. A very dull sound, like, 
for instance, that of a cannon at a great distance, provokes 
merely a luminous sensation without colour. When the 
noise becomes hissing, and more and more acute, the cor- 
responding sensation turns to a red, passing through yellow, 
grey, and blue. 
The intensity of a sound makes the colour more definite. 
When the sound is feeble, the colour seems to experience 
oscillatory movements like those of the air. When the 
sound becomes clear and distinct, the colour also becomes 
uniform and well characterised. 
Words pronounced in conversation call up a colour-sen- 
sation which depends solely on the timbre of the voice. The 
intensity of this sensation is not due to the consonants, 
which, when pronounced separately, excite a chromatic 
sensation scarcely appreciable, but to the vowels. The 
vessels i and e (pronounced, of course, as in Italian, 
German, &c.), are accompanied by the most brilliant 
colours ; on ( 00 ) produces the darkest colour, a and 0 inter- 
mediate colours. The diphthongs are accompanied with a 
