ey soon become associated
together, according to Law the seventh, Section IV. on Animal Causation.
And because their frequency of repetition, if as much sensorial power be
produced during every reiteration as is expended, adds to the facility of
their production.

If a stimulus be repeated at uniform intervals of time, as described in
Sect. XII. 3. 3. the action, whether of our muscles or organs of sense, is
produced with still greater facility or energy; because the sensorial power
of association, mentioned above, is combined with the sensorial power of
irritation; that is, in common language, the acquired habit assists the
power of the stimulus.

This not only obtains in the annual, lunar, and diurnal catenations of
animal motions, as explained in Sect. XXXVI. which are thus performed with
great facility and energy; but in every less circle of actions or ideas, as
in the burthen of a song, or the reiterations of a dance. To the facility
and distinctness, with which we hear sounds at repeated intervals, we owe
the pleasure, which we receive from musical time, and from poetic time; as
described in Botanic Garden, P. 2. Interlude 3. And to this the pleasure we
receive from the rhimes and alliterations of modern verification; the
source of which without this key would be difficult to discover. And to
this likewise should be ascribed the beauty of the duplicature in the
perfect tense of the Greek verbs, and of some Latin ones, as tango tetegi,
mordeo momordi.

There is no variety of notes referable to the gamut in the beating of the
drum, yet if it be performed in musical time, it is agreeable to our ears;
and therefore this pleasurable sensation must be owing to the repetition of
the divisions of the sounds at certain intervals of time, or musical bars.
Whether these times or bars are distinguished by a pause, or by an
emphasis, or accent, certain it is, that this distinction is perpetually
repeated; otherwise the ear could not determine instantly, whether the
successions of sound were in common or in triple time. In common time there
is a division between every two crotchets, or other notes of equivalent
time; though the bar in written music is put after every fourth crotchet,
or notes equivalent in time; in triple time the division or bar is after
every three crotchets, or notes equivalent; so that in common time the
repetition recurs more frequently than in triple time. The grave or heroic
verses of the Greek and Lat