To do this was reserved for the Zendic scholars of a later generation. Rask the Dane in 1826 determined the true form of the genitive plural, and thereby identified the character for _m_ which gave him the names of the supreme god Auramazda and of Achæmenes the forefather of Cyrus.[5] But the great step forward was made by the eminent French scholar, Emile Burnouf, in 1836.[6] The first of the inscriptions published by Niebuhr he discovered to contain a list of the satrapies of Darius. With this clue in his hand the reading of the names and the subsequent identification of the letters which composed them could be a question only of patience and time. For this Burnouf was well equipped by his philological knowledge and training, and the result was an alphabet of thirty letters, the greater part of which had been correctly deciphered. Burnouf’s Memoir on the subject was published in June 1836. In the preceding month his friend and pupil, Professor Lassen of Bonn, had also published a work on “The Old Persian Cuneiform Inscriptions of Persepolis.”[7] He and Burnouf had been in frequent correspondence, and his claim to have independently detected the names of the satrapies, and thereby to have fixed the values of the Persian characters, was in consequence fiercely attacked. To the attacks made upon him, however, Lassen never vouchsafed a reply. Whatever his obligations to Burnouf may have been, his own contributions to the decipherment of the inscriptions were numerous and important. He succeeded in fixing the true values of nearly all the letters in the Persian alphabet, in translating the texts, and in proving that the language of them was not Zend, but stood to both Zend and Sanskrit in the relation of a sister.