Volume 1

The book of the ten treatises on the eye, ascribed to Hunain ibn Is-hâq (809-877 A. D.) : the earliest existing systematic text-book of ophthalmology / the Arabic text edited from the only two known manuscripts, with an English translation and glossary, by Max Meyerhof.

  • Ḥunayn ibn Isḥāq al-ʻIbādī, 809?-873.
Date:
1928
Catalogue details

Licence: Public Domain Mark

Credit: The book of the ten treatises on the eye, ascribed to Hunain ibn Is-hâq (809-877 A. D.) : the earliest existing systematic text-book of ophthalmology / the Arabic text edited from the only two known manuscripts, with an English translation and glossary, by Max Meyerhof. Source: Wellcome Collection.

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    magmation, reflection and recollection, and the movement through it by perception and volition. If it were warm and stirred by all these movements, it would become inflamed and be destroyed. Therefore it has been created cold, that it may not become excessively heated ; (ii) if the brain were warm, the thinking faculty would be unstable, since heat is quick to move, whilst cold is quiet and steady. Thought requires stability and solidity ; therefore Nature assisted thought by tempering it with cold so that it might be steady. The proof of the above statement lies in the fact that he whose temper of brain is hot has no fixed opinion, is undecided, lacking firmness of resolution and stead¬ fastness (of psychical atmosphere). The humidity of the brain is like-wise necessary for two reasons. The first is in order that it may not be dried up by the many move¬ ments accomplished in and through it; for it is a faculty of movement that it produces heat, and a faculty of heat that it produces dryness on account of the great quantity of substance which is thus dissolved and abstracted. The other reason is that Nature necessarily created it soft for many reasons : (i) that it might quickly respond to the imagination and rapidly receive what the senses submitted to it and in order that thought-activity might be possible in it; (ii) a soft nerve proceeds from it through which per¬ ception is effected. Since the soft cannot proceed from the hard nor the hard from the soft, so that brain was distin¬ guished by humidity, because humidity, as we have already mentioned, produces softness. For this reason the anterior part of the brain is softer than the posterior part and the posterior part harder ; for the soft nerves, as we mentioned already, arise in the anterior and the hard nerves in the posterior j)art of the brain. It is this that we wished to explain to you concisely and briefly, concerning the nature and function of the brain. . End of the Second Treatise on the Nature and Function of the Brain, by Hunain I bn Is-hdq. 15 20 25 30 AA u* 5 10