The Notebooks of Leonardo Da Vinci (38 page)

[Footnote: See the sketches and text on Pl. XXXVIII, No. 1. Lines
1-16 are there given on the left hand side, 17-30 on the right. The
four lines at the bottom on the right are given as No. 472. Above
these texts, which are written backwards, there are in the original
sixteen lines in a larger writing from left to right, but only half
of this is here visible. They treat of the physical laws of motion
of air and water. It does not seem to me that there is any reason
for concluding that this writing from left to right is spurious.
Compare with it the facsimile of the rough copy of Leonardo's letter
to Ludovico il Moro in Vol. II.]

611.

People were to be seen eagerly embarking victuals on various kinds
of hastily made barks. But little of the waves were visible in those
places where the dark clouds and rain were reflected.

But where the flashes caused by the bolts of heaven were reflected,
there were seen as many bright spots, caused by the image of the
flashes, as there were waves to reflect them to the eye of the
spectator.

The number of the images produced by the flash of lightning on the
waves of the water were multiplied in proportion to the distance of
the spectator's eye.

So also the number of the images was diminished in proportion as
they were nearer the eye which saw them [Footnote 22. 23:
Com'e
provato
. See Vol. II, Nos. 874-878 and 892-901], as it has been
proved in the definition of the luminosity of the moon, and of our
marine horizon when the sun's rays are reflected in it and the eye
which receives the reflection is remote from the sea.

Of chalk and paper (612—617).

612.

To make points [crayons] for colouring dry. Temper with a little wax
and do not dry it; which wax you must dissolve with water: so that
when the white lead is thus tempered, the water being distilled, may
go off in vapour and the wax may remain; you will thus make good
crayons; but you must know that the colours must be ground with a
hot stone.

613.

Chalk dissolves in wine and in vinegar or in aqua fortis and can be
recombined with gum.

614.

Take powdered gall nuts and vitriol, powder them and spread them on
paper like a varnish, then write on it with a pen wetted with
spittle and it will turn as black as ink.

615.

If you want to make foreshortened letters stretch the paper in a
drawing frame and then draw your letters and cut them out, and make
the sunbeams pass through the holes on to another stretched paper,
and then fill up the angles that are wanting.

616.

This paper should be painted over with candle soot tempered with
thin glue, then smear the leaf thinly with white lead in oil as is
done to the letters in printing, and then print in the ordinary way.
Thus the leaf will appear shaded in the hollows and lighted on the
parts in relief; which however comes out here just the contrary.

[Footnote: This text, which accompanies a facsimile impression of a
leaf of sage, has already been published in the
Saggio delle Opere
di L. da Vinci
, Milano 1872, p. 11. G. GOVI observes on this
passage: "_Forse aveva egli pensato ancora a farsi un erbario, od
almeno a riprodurre facilmente su carta le forme e i particolari
delle foglie di diverse piante; poiche (modificando un metodo che
probabilmente gli eia stato insegnato da altri, e che piu tardi si
legge ripetuto in molti ricettarii e libri di segreti), accanto a
una foglia di Salvia impressa in nero su carta bianca, lascio
scritto: Questa carta …

Erano i primi tentativi di quella riproduzione immediata delle parti
vegetali, che poi sotto il nome d'Impressione Naturale, fu condotta
a tanta perfezione in questi ultimi tempi dal signor de Hauer e da
altri_."]

617.

Very excellent will be a stiff white paper, made of the usual
mixture and filtered milk of an herb called calves foot; and when
this paper is prepared and damped and folded and wrapped up it may
be mixed with the mixture and thus left to dry; but if you break it
before it is moistened it becomes somewhat like the thin paste
called
lasagne
and you may then damp it and wrap it up and put it
in the mixture and leave it to dry; or again this paper may be
covered with stiff transparent white and
sardonio
and then damped
so that it may not form angles and then covered up with strong
transparent size and as soon as it is firm cut it two fingers, and
leave it to dry; again you may make stiff cardboard of
sardonio
and dry it and then place it between two sheets of papyrus and break
it inside with a wooden mallet with a handle and then open it with
care holding the lower sheet of paper flat and firm so that the
broken pieces be not separated; then have a sheet of paper covered
with hot glue and apply it on the top of all these pieces and let
them stick fast; then turn it upside down and apply transparent size
several times in the spaces between the pieces, each time pouring in
first some black and then some stiff white and each time leaving it
to dry; then smooth it and polish it.

On the preparation and use of colours (618-627).

618.

To make a fine green take green and mix it with bitumen and you will
make the shadows darker. Then, for lighter [shades] green with
yellow ochre, and for still lighter green with yellow, and for the
high lights pure yellow; then mix green and turmeric together and
glaze every thing with it. To make a fine red take cinnabar or red
chalk or burnt ochre for the dark shadows and for the lighter ones
red chalk and vermilion and for the lights pure vermilion and then
glaze with fine lake. To make good oil for painting. One part of
oil, one of the first refining and one of the second.

619.

Use black in the shadow, and in the lights white, yellow, green,
vermilion and lake. Medium shadows; take the shadow as above and mix
it with the flesh tints just alluded to, adding to it a little
yellow and a little green and occasionally some lake; for the
shadows take green and lake for the middle shades.

[Footnote 618 and 619: If we may judge from the flourishes with
which the writing is ornamented these passages must have been
written in Leonardo's youth.]

620.

You can make a fine ochre by the same method as you use to make
white.

621.

Dissolve realgar with one part of orpiment, with aqua fortis.

Put the white into an earthen pot, and lay it no thicker than a
string, and let it stand in the sun undisturbed for 2 days; and in
the morning when the sun has dried off the night dews.

622.

To make reddish black for flesh tints take red rock crystals from
Rocca Nova or garnets and mix them a little; again armenian bole is
good in part.

623.

The shadow will be burnt ,terra-verte'.

624.

If one ounce of black mixed with one ounce of white gives a certain
shade of darkness, what shade of darkness will be produced by 2
ounces of black to 1 ounce of white?

625.

Remix black, greenish yellow and at the end blue.

626.

Verdigris with aloes, or gall or turmeric makes a fine green and so
it does with saffron or burnt orpiment; but I doubt whether in a
short time they will not turn black. Ultramarine blue and glass
yellow mixed together make a beautiful green for fresco, that is
wall-painting. Lac and verdigris make a good shadow for blue in oil
painting.

627.

Grind verdigris many times coloured with lemon juice and keep it
away from yellow (?).

Of preparing the panel.

628.

The panel should be cypress or pear or service-tree or walnut. You
must coat it over with mastic and turpentine twice distilled and
white or, if you like, lime, and put it in a frame so that it may
expand and shrink according to its moisture and dryness. Then give
it [a coat] of aqua vitae in which you have dissolved arsenic or
[corrosive] sublimate, 2 or 3 times. Then apply boiled linseed oil
in such a way as that it may penetrate every part, and before it is
cold rub it well with a cloth to dry it. Over this apply liquid
varnish and white with a stick, then wash it with urine when it is
dry, and dry it again. Then pounce and outline your drawing finely
and over it lay a priming of 30 parts of verdigris with one of
verdigris with two of yellow.

[Footnote: M. RAVAISSON'S reading varies from mine in the following
passages:

1.
opero allor [?] bo [alloro?]
= "
ou bien de [laurier]
."

6.
fregalo bene con un panno
. He reads
pane
for
panno
and
renders it. "
Frotte le bien avec un pain de facon [jusqu'a ce]
qu'il
" etc.

7.
colla stecca po laua
. He reads "
polacca
" = "
avec le couteau
de bois [?] polonais [?]
."]

The preparation of oils (629—634).

629.

Make some oil of mustard seed; and if you wish to make it with
greater ease mix the ground seeds with linseed oil and put it all
under the press.

630.

Take the rank oil and put ten pints into a jar and make a mark on
the jar at the height of the oil; then add to it a pint of vinegar
and make it boil till the oil has sunk to the level of the mark and
thus you will be certain that the oil is returned to its original
quantity and the vinegar will have gone off in vapour, carrying with
it the evil smell; and I believe you may do the same with nut oil or
any other oil that smells badly.

631.

Since walnuts are enveloped in a thin rind, which partakes of the
nature of …, if you do not remove it when you make the oil from
them, this skin tinges the oil, and when you work with it this skin
separates from the oil and rises to the surface of the painting, and
this is what makes it change.

632.

If you want to restore oil colours that have become dry keep them
soaking in soft soap for a night and, with your finger, mix them up
with the soft soap; then pour them into a cup and wash them with
water, and in this way you can restore colours that have got dry.
But take care that each colour has its own vessel to itself adding
the colour by degrees as you restore it and mind that they are
thoroughly softened, and when you wish to use them for tempera wash
them five and six times with spring water, and leave them to settle;
if the soft soap should be thick with any of the colours pass it
through a filter. [Footnote: The same remark applies to these
sections as to No. 618 and 619.]

633.

Mustard seed pounded with linseed oil.

634.

… outside the bowl 2 fingers lower than the level of the oil, and
pass it into the neck of a bottle and let it stand and thus all the
oil will separate from this milky liquid; it will enter the bottle
and be as clear as crystal; and grind your colours with this, and
every coarse or viscid part will remain in the liquid. You must know
that all the oils that have been created in seads or fruits are
quite clear by nature, and the yellow colour you see in them only
comes of your not knowing how to draw it out. Fire or heat by its
nature has the power to make them acquire colour. See for example
the exudation or gums of trees which partake of the nature of rosin;
in a short time they harden because there is more heat in them than
in oil; and after some time they acquire a certain yellow hue
tending to black. But oil, not having so much heat does not do so;
although it hardens to some extent into sediment it becomes finer.
The change in oil which occurs in painting proceeds from a certain
fungus of the nature of a husk which exists in the skin which covers
the nut, and this being crushed along with the nuts and being of a
nature much resembling oil mixes with it; it is of so subtle a
nature that it combines with all colours and then comes to the
surface, and this it is which makes them change. And if you want the
oil to be good and not to thicken, put into it a little camphor
melted over a slow fire and mix it well with the oil and it will
never harden.

[Footnote: The same remark applies to these sections as to No. 618
and 619.]

On varnishes [or powders] (635-637).

635.

Take cypress [oil] and distil it and have a large pitcher, and put
in the extract with so much water as may make it appear like amber,
and cover it tightly so that none may evaporate. And when it is
dissolved you may add in your pitcher as much of the said solution,
as shall make it liquid to your taste. And you must know that amber
is the gum of the cypress-tree.

And since varnish [powder] is the resin of juniper, if you distil
juniper you can dissolve the said varnish [powder] in the essence,
as explained above.

636.

Notch a juniper tree and give it water at the roots, mix the liquor
which exudes with nut-oil and you will have a perfect varnish
[powder], made like amber varnish [powder], fine and of the best
quality make it in May or April.

637.

Mercury with Jupiter and Venus,—a paste made of these must be
corrected by the mould (?) continuously, until Mercury separates
itself entirely from Jupiter and Venus. [Footnote: Here, and in No.
641
Mercurio
seems to mean quicksilver,
Giove
stands for iron,
Venere
for copper and
Saturno
for lead.]

On chemical materials (638-650).