Remember, you've got to begin on the demisemiquaver at the end of the bar -- only not too staccato, remember -- and allow for the pause.    From Wordnik.com.  [Somehow Good] Reference

But you must not vigorously move immediately from semiquavers to demisemiquavers, as in this example, or from these to the next in degree -- that would be doubling the velocity of the shake all at once, which would be a skip, not a graduation; but you can imagine between a semiquaver and a demisemiquaver intermediate degrees of rapidity, quicker than the one, and slower than the other of these characters; you are therefore to increase in velocity by the same degrees in practising the shake, as in loudness when you make a swell.    From Wordnik.com.  [The Violin Its Famous Makers and Their Imitators] Reference

6f.; a crotchet, 3f.; a quaver, 1f. 50c.; a semiquaver, 15 sous; a demisemiquaver, 7-1/2 sous.    From Wordnik.com.  [The Mirror of Literature, Amusement, and Instruction Volume 17, No. 491, May 28, 1831] Reference

Not lose a demisemiquaver.    From Wordnik.com.  [Ulysses] Reference

List of Words and Phrases demeanour, 221 demisemiquaver, 132 demoralize, 59 demote, v.    From Wordnik.com.  [Mencken, H] Reference