THE HCMAN COLOUR SENSE. 175 



mathematical, and pi'actical musicians cannot a.gree upon. If we 

 were to go hj what mathematicians tell us we should have, in 

 organs, about fifty notes to every octave, which would be 

 practically impossible, and which no musician requires, and the 

 fact whether music would be possible under such conditions is an 

 open question, but the tempered scale throughout music is, as I 

 have said. 



One point in regard to discord. Musicians have got a way of 

 talking of concord and discord, the idea, appai-ently, being that 

 discord is something unpleasant to the ear ; but that is not so at 

 all. The most disagreeable sound you can have in music is a 

 perfect fifth bj- itself, and that is what all technical musicians call 

 a concord ; but I think when there is a discordant sound the ear 

 requires some particular note to follow, or one of a particular 

 series of notes. 



Dr. Macdonald. — No' doubt the question of tempei^ament you 

 have taken up is very important and one of some difiiculty, so as 

 to admit of modulation. A scale such as I have given here is 

 limited to C, and you cannot apply it in any other key with the 

 vibrations this way [explaining on the diagram'], but you may take 

 an equal tempei'ament, or some principle which enables you to 

 give a serai-tone at equal distances apart. It is rather difficult in 

 some instances, for you would require an infinite number of key- 

 boards, or pipes, or notes, as the case may be. 



Mr. Thelwall. — I only thought it important to distinguish 

 between the theoretical scale and the sounds that we hear. 



The Hev. A. K. Cherrill, M.A. — I should like to ask one or 

 two questions about this table. If you divide two scales propor- 

 tionally they would be proportional when you divide them ; but I 

 do not quite understand how you select this so-called scale. I 

 suppose the musician selects the notes by ear. You cannot draw 

 a fine line and say, " This is red and this is orange." 



Dr. Macdoxald. — Yes ; you take the musical ratio and you do it 

 at once. 



The Rev. A. K. Cherrill. — E.xiactly ; if you take the musical 

 ratio. But if you take the musical ratio of course that corresponds. 

 I do not quite see where the point comes in there. I do not see 

 where the visual point, with regard to the light, comes in. 



Dr. Macdonald. — In regard to the monochord, whatever scale is 

 adopted that will be found to be the test of the monochord. The 



