Professor M. Inostranzev was a Russian scholar. He shared with Professor Browne of Cambridge and the great M. Blochet a unique scholarly position: he combined an intimate knowledge of Avesta civilization with a familiarity with classical Arabic. It is not wilfully to ignore the claims of Goldziher, Brockelmann or Sachau or the Dutch savants de Goeje and Van Vloten. Deeply as they investigated Arabic writings, it was M. Inostranzev who first revealed to us the worth of Arabic: he unearthed chapters embedded in Arabic books which are paraphrase or translation of Pahlavi originals. He had but one predecessor and that was a countryman of his, Baron Rosen.