The Notebooks of Leonardo Da Vinci

Page 1491

Hippocrates says that the origin of men's sperm derives from the
brain, and from the lungs and testicles of our parents, where the
final decocture is made, and all the other limbs transmit their
substance to this sperm by means of expiration, because there are no
channels through which they might come to the sperm.

[Footnote: The works of Hippocrates were printed first after
Leonardo's death.]

Page 1490

of in relation to the whole; and all their relations lie between
these two extremes, and are called multiples.

Page 1489

5th Book of Euclid. First definition: a part is a quantity of less
magnitude than the greater magnitude when the less is contained a
certain number of times in the greater.

A part properly speaking is that which may be multiplied, that is
when, being multiplied by a certain number, it forms exactly the
whole. A common aggregate part ...

Second definition. A greater magnitude is said to be a multiple of a
less, when the greater is measured by the less.

By the first we define the lesser [magnitude] and by the second the
greater is defined. A part is spoken

Page 1488

Maestro Stefano Caponi, a physician, lives at the piscina, and has
Euclid _De Ponderibus_.

Page 1487

Demetrius was wont to say that there was no difference between the
speech and words of the foolish and ignorant, and the noises and
rumblings of the wind in an inflated stomach. Nor did he say so
without reason, for he saw no difference between the parts whence
the noise issued; whether their lower parts or their mouth, since
one and the other were of equal use and importance.

[Footnote: Compare Vol. I, No. 10.]

Page 1486

CORNELIUS CELSUS.

The highest good is wisdom, the chief evil is suffering in the body.
Because, as we are composed of two things, that is soul and body, of
which the first is the better, the body is the inferior; wisdom
belongs to the better part, and the chief evil belongs to the worse
part and is the worst of all. As the best thing of all in the soul
is wisdom, so the worst in the body is suffering. Therefore just as
bodily pain is the chief evil, wisdom is the chief good of the soul,
that is with the wise man; and nothing else can be compared with it.

[Footnote: _Aulus Cornelius Celsus_, a Roman physician, known as the
Roman Hippocrates, probably contemporary with Augustus. Only his
eight Books 'De Medicina', are preserved. The earliest editions are:
_Cornelius Celsus, de medicina libr. VIII._, Milan 1481 Venice 1493
and 1497.]

Page 1485

Cleomedes the philosopher.

[Footnote: Cleomede. A Greek mathematician of the IVth century B. C.
We have a Cyclic theory of Meteorica by him. His works were not
published before Leonardo's death.]

Page 1484

Roger Bacon, done in print. [Footnote: The earliest printed edition
known to Brunet of the works of Roger Bacon, is a French
translation, which appeared about fourty years after Leonardo's
death.]

Page 1483

Avicenna on liquids.

Page 1482

Avicenna will have it that soul gives birth to soul as body to body,
and each member to itself.

[Footnote: Avicenna, see too No. 1421, 1. 2.]

Page 1481

On the increase of the Nile, a small book by Aristotle. [Footnote:
_De inundatione Nili_, is quoted here and by others as a work of
Aristotle. The Greek original is lost, but a Latin version of the
beginning exists (Arist. Opp. IV p. 213 ed. Did. Par.).

In his quotations from Aristotle Leonardo possibly refers to one of
the following editions: _Aristotelis libri IV de coelo et mundo; de
anima libri III; libri VIII physi- corum; libri de generatione et
corruptione; de sensu et sensato... omnia latine, interprete
Averroe, Venetiis 1483_ (first Latin edition). There is also a
separate edition of _Liber de coelo et mundo_, dated 1473.]

Page 1480

Aristotle says that every body tends to maintain its nature.

Page 1479

Aristotle in Book 3 of the Ethics: Man merits praise or blame solely
in such matters as lie within his option to do or not to do.

Page 1478

Aristotle says that if a force can move a body a given distance in a
given time, the same force will move half the same body twice as far
in the same time.

Page 1477

Aristotle, Book 3 of the Physics, and Albertus Magnus, and Thomas
Aquinas and the others on the rebound of bodies, in the 7th on
Physics, on heaven and earth.

Page 1476

If any man could have discovered the utmost powers of the cannon, in
all its various forms and have given such a secret to the Romans,
with what rapidity would they have conquered every country and have
vanquished every army, and what reward could have been great enough
for such a service! Archimedes indeed, although he had greatly
damaged the Romans in the siege of Syracuse, nevertheless did not
fail of being offered great rewards from these very Romans; and when
Syracuse was taken, diligent search was made for Archimedes; and he
being found dead greater lamentation was made for him by the Senate
and people of Rome than if they had lost all their army; and they
did not fail to honour him with burial and with a statue. At their
head was Marcus Marcellus. And after the second destruction of
Syracuse, the sepulchre of Archimedes was found again by Cato[25],
in the ruins of a temple. So Cato had the temple restored and the
sepulchre he so highly honoured.... Whence it is written that Cato
said that he was not so proud of any thing he had done as of having
paid such honour to Archimedes.

[Footnote: Where Leonardo found the statement that Cato had found
and restored the tomb of Archimedes, I do not know. It is a merit
that Cicero claims as his own (Tusc. V, 23) and certainly with a
full right to it. None of Archimedes' biographers --not even the
diligent Mazzucchelli, mentions any version in which Cato is named.
It is evidently a slip of the memory on Leonardo's part. Besides,
according to the passage in Cicero, the grave was not found _'nelle
ruine d'un tempio'_--which is highly improbable as relating to a
Greek--but in an open spot (H. MULLER-STRUBING).--See too, as to
Archimedes, No. 1417.

Leonardo says somewhere in MS. C.A.: _Architronito e una macchina di
fino rame, invenzlon d' Archimede_ (see _'Saggio'_, p. 20).]