According to this list the scriptures of Iran must have been of very considerable extent. The Arabian author Masudi, who lived about the middle of the tenth century A.D., also puts the number of books at twenty-one. "Zartusht," he says, "gave the Parsees the book which is called the Avesta. It consisted of twenty-one sections, of which each amounted to 200 pages. This book was written in the character which Zartusht invented and which the Magians call the religious character, on 12,000 cow-hides, and these were kept together by bands of gold. It was composed in the old Persian language, which no one now understands."[82] From the list of the books and chapters it is clear that these writings comprised not only the religious doctrine and law, together with the rules for correct conversation, but also the rubrics for the liturgy and ritual. They were at the same time the code of criminal and civic law, and in them was deposited what was known of medicine and agriculture, and the sum total of the science of their authors. Can we assume that writings of this importance, nature, and extent existed in Iran before Alexander of Macedon overthrew the kingdom of the Achæmenids? Herodotus tells us that the Magians or priests of the Persians recited the theogony, _i.e._ long poems, at their sacrifices. The disciples of the sophist Prodicus are said to have asserted that they were in possession of writings of Zoroaster, who taught the Persians their religion.[83] Hermippus of Smyrna, who wrote in the second half of the third century B.C., and devoted especial attention to the religions of the east, stated that the Magians maintained two principles, a good and an evil deity; the one they called Zeus and Oromasdes, the other Hades and Areimanius.[84] Zoroaster, who founded the doctrine of the Magians, had composed twenty books, each of 100,000 lines, and Hermippus gave the contents of the various books and quoted regulations from them. Pliny tells us: "The doctrine of the Magians prevails to this day among a great part of the nations, and in the East is supreme over the king of kings" (_i.e._ the Arsacids); and vouches for Hermippus that he had written with great care about the Magians,[85] from whose work no doubt he quotes some particulars of the doctrine of Zoroaster. According to Zoroaster's rule the sowing of the fields should take place when the moon is in the sign of Taurus; and it was forbidden to expose the person before the sun or moon, or to defile a man's shadow. Pliny also mentions the precious stones, of which Zoroaster had extolled the brilliance; the herbs, used by the Magians; and enumerates a number of remedies, which they applied. Finally, he speaks of the Nyktegertos, a herb growing in Gedrosia, which the Magians used when making vows.[86] Philo of Byblus quotes a passage, apparently from "the sacred collection of Zoroaster," on the nature of the deity, and assures us that the Persian Osthanes maintained the same in the Octateuch.[87]