that for the same
individual reactions were constant. Circulatory reaction was more often
manifest than respiratory reaction. The latter might be either a
simultaneous modification of depth and of rapidity or of either of these.
The circulatory reaction was a peripheral vasoconstriction with diminished
fullness of pulse and slight acceleration of cardiac rhythm; there was
never any distinct slowing of heart under the influence of music. Guibaud
remarks that when people say they feel a shudder at some passage of music,
this sensation of cold finds its explanation in the production of a
peripheral vasoconstriction which may be registered by the
plethysmograph.[105]

Since music thus directly and powerfully affects the chief vital
processes, it is not surprising that it should indirectly influence
various viscera and functions. As Tarchanoff and others have demonstrated,
it affects the skin, increasing the perspiration; it may produce a
tendency to tears; it sometimes produces desire to urinate, or even actual
urination, as in Scaliger's case of the Gascon gentleman who was always
thus affected on hearing the bagpipes. In dogs it has been shown by
Tarchanoff and Wartanoff that auditory stimulation increases the
consumption of oxygen 20 per cent., and the elimination of carbonic acid
17 per cent.

In addition to the effects of musical sound already mentioned, it may be
added that, as Epstein, of Berne, has shown,[106] the other senses are
stimulated under the influence of sound, and notably there is an increase
in acuteness of vision which may be experimentally demonstrated. It is
probable that this effect of music in heightening the impressions received
by the other senses is of considerable significance from our present point
of view.

Why are musical tones in a certain order and rhythm pleasurable? asked
Darwin in _The Descent of Man_, and he concluded that the question was
insoluble. We see that, in reality, whatever the ultimate answer may be,
the immediate reason is quite simple. Pleasure is a condition of slight
and diffused stimulation, in which the heart and breathing are faintly
excited, the neuro-muscular system receives additional tone, the viscera
gently stirred, the skin activity increased; and certain combinations of
musical notes and intervals act as a physiological stimulus in producing
these effects.[107]

Among animals of all kinds, from insects upward, this physiological action
appears to exist, fo