The Notebooks of Leonardo da Vinci

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. 799. THE ARRANGEMENT OF ANATOMY First draw the bones, let us say, of the arm, and put in the motor muscle from the shoulder to the elbow with all its lines. Then proceed in the same way from the elbow to the wrist. Then from the wrist to the hand and from the hand to the fingers. And in the arm you will put the motors of the fingers which open, and these you will show separately in their demonstration. In the second demonstration you will clothe these muscles with the secondary motors of the fingers and so proceed by degrees to avoid confusion. But first lay on the bones those muscles which lie close to the said bones, without confusion of other muscles; and with these you may put the nerves and veins which supply their nourishment, after having first drawn the tree of veins and nerves over the simple bones. 800. Begin the anatomy at the head and finish at the sole of the foot. 801. 3 men complete, 3 with bones and nerves, 3 with the bones only. Here we have 12 demonstrations of entire figures. 802. When you have finished building up the man, you will make the statue with all its superficial measurements. [Footnote: Cresciere l'omo. The meaning of this expression appears to be different here and in the passage C.A. 157a, 468a (see No. 526, Note 1. 2). Here it can hardly mean anything else than modelling, since the sculptor forms the figure by degrees, by adding wet clay and the figure consequently increases or grows. Tu farai la statua would then mean, you must work out the figure in marble. If this interpretation is the correct one, this passage would have no right to find a place in the series on anatomical studies. I may say that it was originally inserted in this connection under the impression that di cresciere should be read descrivere.] Plans for the representation of muscles by drawings (803-809). 803. You must show all the motions of the bones with their joints to follow the demonstration of the first three figures of the bones, and this should be done in the first book. 804. Remember that to be certain of the point of origin of any muscle, you must pull the sinew from which the muscle springs in such a way as to see that muscle move, and where it is attached to the ligaments of the bones. NOTE. You will never get any thing but confusion in demonstrating the muscles and their positions, origin, and termination, unless you first make a demonstration of thin muscles after the manner of linen threads; and thus you can represent them, one over another as nature has placed them; and thus, too, you can name them according to the limb they serve; for instance the motor of the point of the great toe, of its middle bone, of its first bone, &c. And when you have the knowledge you will draw, by the side of this, the true form and size and position of each muscle. But remember to give the threads which explain the situation of the muscles in the position which corresponds to the central line of each muscle; and so these threads will demonstrate the form of the leg and their distance in a plain and clear manner. I have removed the skin from a man who was so shrunk by illness that the muscles were worn down and remained in a state like thin membrane, in such a way that the sinews instead of merging in muscles ended in wide membrane; and where the bones were covered by the skin they had very little over their natural size. [Footnote: The photograph No. 41 of Grosvenor Gallery Publications: a drawing of the muscles of the foot, includes a complete facsimile of the text of this passage.] 805. Which nerve causes the motion of the eye so that the motion of one eye moves the other? Of frowning the brows, of raising the brows, of lowering the brows,—of closing the eyes, of opening the eyes,—of raising the nostrils, of opening the lips, with the teeth shut, of pouting with the lips, of smiling, of astonishment.— Describe the beginning of man when it is caused in the womb and why an eight months child does not live. What sneezing is. What yawning is. Falling sickness, spasms, paralysis, shivering with cold, sweating, fatigue, hunger, sleepiness, thirst, lust. Of the nerve which is the cause of movement from the shoulder to the elbow, of the movement from the elbow to the hand, from the joint of the hand to the springing of the fingers. From the springing of the fingers to the middle joints, and from the middle joints to the last. Of the nerve which causes the movement of the thigh, and from the knee to the foot, and from the joint of the foot to the toes, and then to the middle of the toes and of the rotary motion of the leg. 806. ANATOMY. Which nerves or sinews of the hand are those which close and part the fingers and toes latteraly? 807. Remove by degrees all the parts of the front of a man in making your dissection, till you come to the bones. Description of the parts of the bust and of their motions. 808. Give the anatomy of the leg up to the hip, in all views and in every action and in every state; veins, arteries, nerves, sinews and muscles, skin and bones; then the bones in sections to show the thickness of the bones. [Footnote: A straightened leg in profile is sketched by the side of this text.] On corpulency and leanness (809-811). 809. Make the rule and give the measurement of each muscle, and give the reasons of all their functions, and in which way they work and what makes them work &c. [4] First draw the spine of the back; then clothe it by degrees, one after the other, with each of its muscles and put in the nerves and arteries and veins to each muscle by itself; and besides these note the vertebrae to which they are attached; which of the intestines come in contact with them; and which bones and other organs &c. The most prominent parts of lean people are most prominent in the muscular, and equally so in fat persons. But concerning the difference in the forms of the muscles in fat persons as compared with muscular persons, it shall be described below. [Footnote: The two drawings given on Pl. CVIII no. 1 come between lines 3 and 4. A good and very early copy of this drawing without the written text exists in the collection of drawings belonging to Christ's College Oxford, where it is attributed to Leonardo.] 810. Describe which muscles disappear in growing fat, and which become visible in growing lean. And observe that that part which on the surface of a fat person is most concave, when he grows lean becomes more prominent. Where the muscles separate one from another you must give profiles and where they coalesce … 811. OF THE HUMAN FIGURE. Which is the part in man, which, as he grows fatter, never gains flesh? Or what part which as a man grows lean never falls away with a too perceptible diminution? And among the parts which grow fat which is that which grows fattest? Among those which grow lean which is that which grows leanest? In very strong men which are the muscles which are thickest and most prominent? In your anatomy you must represent all the stages of the limbs from man's creation to his death, and then till the death of the bone; and which part of him is first decayed and which is preserved the longest. And in the same way of extreme leanness and extreme fatness. The divisions of the head (812. 813). 812. ANATOMY. There are eleven elementary tissues:— Cartilage, bones, nerves, veins, arteries, fascia, ligament and sinews, skin, muscle and fat. OF THE HEAD. The divisions of the head are 10, viz. 5 external and 5 internal, the external are the hair, skin, muscle, fascia and the skull; the internal are the dura mater, the pia mater, [which enclose] the brain. The pia mater and the dura mater come again underneath and enclose the brain; then the rete mirabile, and the occipital bone, which supports the brain from which the nerves spring. 813. a. hair n. skin c. muscle m. fascia o. skull i.e. bone b. dura mater d. pia mater f. brain r. pia mater, below t. dura mater l. rete mirablile s. the occipitul bone. [Footnote: See Pl. CVIII, No. 3.] Physiological problems (814. 815). 814. Of the cause of breathing, of the cause of the motion of the heart, of the cause of vomiting, of the cause of the descent of food from the stomach, of the cause of emptying the intestines. Of the cause of the movement of the superfluous matter through the intestines. Of the cause of swallowing, of the cause of coughing, of the cause of yawning, of the cause of sneezing, of the cause of limbs getting asleep. Of the cause of losing sensibility in any limb. Of the cause of tickling. Of the cause of lust and other appetites of the body, of the cause of urine and also of all the natural excretions of the body. [