The long line of scholars from Münter to Jacquet, whose labours we have now passed in review, had at length succeeded in deciphering the cuneiform alphabet of the first species of writing found at Persepolis, and, with the exception of two, they had attached correct values to each of the thirty-five letters. When, therefore, Lassen wrote his second Memoir, the task he had to perform was concerned much less with the alphabet than with the numerous strange words formed by it, which it was now necessary to assign a meaning to and connect together by grammatical rules. It is clear there was only one method to pursue, and that was to compare them with the words and forms of other languages with which the Old Persian was likely to be connected. It was natural in the first instance to turn to Zend, the sacred language of the country in which the inscriptions were found; and the most superficial comparison, which was all that was then possible, was sufficient to prove that the two languages were closely allied. The early scholars were, however, greatly impeded by the extremely imperfect knowledge of Zend that as yet prevailed; and even if the cuneiform alphabet had been completely deciphered by Grotefend, it may be doubted whether the means were then available to grapple successfully with the difficulties of translation.[522] At that time Zend was known only by the work of Duperron, which, however remarkable for the time at which it appeared, was quite inadequate for the purpose. Indeed some scholars, even long afterwards, had doubts as to the genuineness of the language itself. Since then, however, the edition of the Yaçna published by Burnouf in 1833 placed the study upon an entirely different footing; and the progress made by Bopp and many others in Sanscrit was also of material service. It thus happened that concurrently with the improvement of the cuneiform alphabet the chief obstacles to the translation of the language were removed. When Burnouf and Lassen wrote their Memoirs in 1836, little progress had been made in that direction beyond the identification of the names of the Achaemenian kings, and of a few simple words. The attempt to go beyond rested chiefly upon conjecture and frequently resulted in absurdities of which the constellation of Moro is the typical instance.[523]