re body can move if it has not a stable spot whence it may
take its motion, and more especially is this the case when an element
must move in its own element, which does not move of itself, excepting
by uniform evaporation at the centre of the thing evaporated; as occurs
in the case of the sponge squeezed in the hand under water, whence the
water escapes in every direction with equal motion through the spaces
between the fingers of the hand which squeezes it. As to whether the
spirit has an articulate voice and can be heard, and as to what are
hearing and sight--the wave of the voice travels through the air as the
images of objects travel to the eye.

{189}

110.

O mathematicians, clear up this error! The spirit cannot have a voice,
for where there is a voice there is a body, and where there is a body
there is occupation of space, which prevents the eye seeing what is
behind that space; therefore a body fills all the surrounding air, that
is to say, with its own image.

111.

There can be no voice where there is no motion or percussion of the
air, there can be no percussion of the air where there is no
instrument, there can be no such thing as an immaterial instrument; and
this being so, a spirit can have neither voice, nor shape, nor force;
and if it assumes a shape it can neither penetrate nor enter where the
issues are closed. If any one were to say that a spirit may take
bodies of various shapes by means of concentrated and compressed air,
and by means of this instrument speak and move with force--I reply to
this argument that where there are no nerves or bones, no force can be
expended in any movement made by these imaginary spirits.

{193}

BIBLIOGRAPHICAL NOTE

AND

TABLE OF REFERENCES

BIBLIOGRAPHICAL NOTE

* *
*

Only of late years have the manuscripts of Leonardo da Vinci seen the
light and the many difficulties been overcome which long proved an
obstacle to their publication. The labour of editing, deciphering and
translating his many scattered and fragmentary codices was beyond the
efforts of any single man. The gratitude of the cultivated world is
therefore due to those who, like J. P. Richter, C. Kavaisson-Mollien,
Luca Beltrami, Piumati, Sabachnikoff, and, last but not least, the
scholars of the Academia del Lincei, have so faithfully devoted
themselves to this task, which alone has made possible the present
little work.

It was unavoidable that the form i