_Jabel Nakous_, and a slope of many yards, to produce. But in the
stillness of a close room, it is just possible that it may. I have,
however, little doubt, that from small quantities the sound evoked by
the foot on the shore may be reproduced: enough will lie within the
reach of experiment to demonstrate the strange difference which exists
between this sonorous sand of the Oolite, and the common unsonorous sand
of our sea-beaches; and it is certainly worth while examining into the
nature and producing causes of a phenomenon so curious in itself, and
which has been characterized by one of the most distinguished of living
philosophers as "the most celebrated of all the acoustic wonders which
the natural world presents to us." In the forthcoming number of the
"North British Review,"--which appears on Monday first,[1]--the reader
will find the sonorous sand of Eigg referred to, in an article the
authorship of which will scarcely be mistaken. "We have here," says the
writer, after first describing the sounds of _Jabel Nakous_, and then
referring to those of Eigg, "the phenomenon in its simple state,
disembarrassed from reflecting rocks, from a hard bed beneath, and from
cracks and cavities that might be supposed to admit the sand; and
indicating as its cause, either the accumulated vibration of the air
when struck by the driven sand, or the accumulated sounds occasioned by
the mutual impact of the particles of sand against each other. If a
musket-ball passing through the air emits a whistling note, each
individual particle of sand must do the same, however faint be the note
which it yields; and the accumulation of these infinitesimal vibrations
must constitute an audible sound, varying with the number and velocity
of moving particles. In like manner, if two plates of silex or quartz,
which are but large crystals of sand, give out a musical sound when
mutually struck, the impact or collision of two minute crystals or
particles of sand must do the same, in however inferior a degree; and
the union of all these sounds, though singly imperceptible, may
constitute the musical notes of the Bell Mountain, or the lesser sounds
of the trodden sea-beach at Eigg."

Here is a vigorous effort made to unlock the difficulty. I should,
however, have mentioned to the philosophic writer,--what I inadvertently
failed to do,--that the sounds elicited from the sand of Eigg seem as
directly evoked by the slant blow dealt it by the foot, as the sou