Xenophon’s treatise on _The Horse_ had been preceded by a similar work by Simon;[606] he himself also wrote on _Hunting_, on _The Duties of a Cavalry Officer_, on _The Management of a Farm_, and _The Constitution of Sparta_, besides his more definitely historical and philosophical works. His _Education of Kuros_ conceals a treatise on the duties of a general. The subjects are significant of the new movement; for earlier Hellenes had supposed that Homer and Hesiod taught the whole art of agriculture and generalship. Other agricultural treatises, containing much theory but very little practical knowledge, were also in circulation.[607] Later in the fourth century Aineias the Tactician contributed a manual for generals. Medical treatises emanated in great numbers from the school of Hippokrates, and probably from elsewhere. Chares and Apollodoros published works on Husbandry,[608] Mithaikos a _Sicilian Cookery-Book_,[609] Metrodoros a book of Homeric allegories. Books of travels and geography are also mentioned by Aristotle.[610] Handbooks on “Rhetoric” were first compiled by Korax and Tisias: they dealt with the subject of “arguments from probability.” Show pieces were written by Antiphon and Gorgias. A treatise by Polos upon the systematic arrangement of a speech was read by Sokrates. Thrasumachos published a work upon _Appeals to Compassion_. The prices were probably not high, for the labour of copying could be cheaply performed by means of slaves. Sokrates, in the Platonic Apology,[611] mentions that a copy of Anaxagoras could sometimes be picked up for a drachma; and there is no reason to suppose that Anaxagoras was particularly cheap. If this was an average price, books must have been within the reach of most Athenians. [529] Isokrates clearly felt them to be his educational rivals. See _Antid._ 310 A, and the end of the _Paneg._ [530] There is a sketch of them in Isok. _Panath._ 236 C; to a lecture on Homer three or four of them had appended an attack upon Isokrates. [531] Isok. _Antid._ 99. [532] Isok. _Soph._ 10. 293 A. [533] Isok. _Soph._ 4. 291 D. Cp. the modern “caution-money.” [534] Isok. _Pan._ 26. 238 A. [535] Isok. _Antid._ 118. 265. [536] Isok. _Panath._ 238 D. [537] Isok. _Antid._ 118. 266. [538] _Ibid._ 118. 268. [539] Isok. _Antid._ 118. 268. [540] _Ibid._ 91. [541] Isok. letter to Alexander. [542] Isok. _Panath._ 275. It is noticeable how many of his pupils became historians――Ephoros, Theopompos, Androtion, Asklepiades. [543] See, for example, “On Slander “(_Antid._ 313 E), “On Speech” (115. 255). [544] Isok. _Antid._ 48. [545] For a complete analysis of it, see Jebb’s _Attic Orators_. [546] Isok. _ag. Soph._ 294 C; _Antid._ 91-93, etc. [547] _Ibid._ 294 E. [548] Isok. _Antid._ 121. [549] Isok. _ag. Soph._ 295 D. [550] Isok. _Areiop._ 151 B.