THE ORDER OF THE BOOK.

This depicting of mine of the human body will be as clear to you as
if you had the natural man before you; and the reason is that if you
wish thoroughly to know the parts of man, anatomically, you--or your
eye--require to see it from different aspects, considering it from
below and from above and from its sides, turning it about and
seeking the origin of each member; and in this way the natural
anatomy is sufficient for your comprehension. But you must
understand that this amount of knowledge will not continue to
satisfy you; seeing the very great confusion that must result from
the combination of tissues, with veins, arteries, nerves, sinews,
muscles, bones, and blood which, of itself, tinges every part the
same colour. And the veins, which discharge this blood, are not
discerned by reason of their smallness. Moreover integrity of the
tissues, in the process of the investigating the parts within them,
is inevitably destroyed, and their transparent substance being
tinged with blood does not allow you to recognise the parts covered
by them, from the similarity of their blood-stained hue; and you
cannot know everything of the one without confusing and destroying
the other. Hence, some further anatomy drawings become necessary. Of
which you want three to give full knowledge of the veins and
arteries, everything else being destroyed with the greatest care.
And three others to display the tissues; and three for the sinews
and muscles and ligaments; and three for the bones and cartilages;
and three for the anatomy of the bones, which have to be sawn to
show which are hollow and which are not, which have marrow and which
are spongy, and which are thick from the outside inwards, and which
are thin. And some are extremely thin in some parts and thick in
others, and in some parts hollow or filled up with bone, or full of
marrow, or spongy. And all these conditions are sometimes found in
one and the same bone, and in some bones none of them. And three you
must have for the woman, in which there is much that is mysterious
by reason of the womb and the foetus. Therefore by my drawings every
part will be known to you, and all by means of demonstrations from
three different points of view of each part; for when you have seen
a limb from the front, with any muscles, sinews, or veins which take
their rise from the opposite side, the same limb will be shown to
you in a side view or from behind, exactly as if you had that same
limb in your hand and were turning it from side to side until you
had acquired a full comprehension of all you wished to know. In the
same way there will be put before you three or four demonstrations
of each limb, from various points of view, so that you will be left
with a true and complete knowledge of all you wish to learn of the
human figure[Footnote 35: Compare Pl. CVII. The original drawing at
Windsor is 28 1/2 X 19 1/2 centimetres. The upper figures are
slightly washed with Indian ink. On the back of this drawing is the
text No. 1140.].

Thus, in twelve entire figures, you will have set before you the
cosmography of this lesser world on the same plan as, before me, was
adopted by Ptolemy in his cosmography; and so I will afterwards
divide them into limbs as he divided the whole world into provinces;
then I will speak of the function of each part in every direction,
putting before your eyes a description of the whole form and
substance of man, as regards his movements from place to place, by
means of his different parts. And thus, if it please our great
Author, I may demonstrate the nature of men, and their customs in
the way I describe his figure.

And remember that the anatomy of the nerves will not give the
position of their ramifications, nor show you which muscles they
branch into, by means of bodies dissected in running water or in
lime water; though indeed their origin and starting point may be
seen without such water as well as with it. But their ramifications,
when under running water, cling and unite--just like flat or hemp
carded for spinning--all into a skein, in a way which makes it
impossible to trace in which muscles or by what ramification the
nerves are distributed among those muscles.