This was a discovery to the learned world as welcome as any that could be made. It was unique in its kind. All attempts, thus far, had vainly sought to learn something about the history of the builders of those palaces and temples with whose ruins the peninsula was covered at the date of the arrival of the Spaniards, and which pointed to a long past and to the unceasing activity of a numberless population, which, while it was skilled in the most important branches of art and industry, and familiar with a luxury such as only ancient Asia and India had displayed, was yet governed by a despotic and hierarchical power. The native, when asked whose work the ruins were, would answer nothing but that they owed their origin to men who, in ancient times, had immigrated from far distant countries. The Manuscript disclosed at once the history of these strange immigrants, showed the progressive march of the conquest, and the contemporaneous foundation of the largest cities then in ruins, and furnished in the Maya language the chronology of each event and its corresponding epoch. By means of his extensive antiquarian knowledge Señor Perez made an exact translation of this Manuscript into Spanish, and afterwards undertook a critical interpretation of its contents, and accompanied the whole with an introductory explanation of the system of ancient Maya chronology. In the midst of these labors he was surprised by the arrival of the celebrated American traveller and archæologist, John Lloyd Stephens, and was induced to entrust to him a copy of the MSS. and interpretations to be embodied in his work on Yucatan, in order to bring them more fully before the world. His wishes were scrupulously complied with, and the Spanish translation has been rendered into literal English by Mr. Stephens in “Incidents of Travel in Yucatan,” vol. I., Appendix, pages 434–459, and vol. II., Appendix, pages 465–469. Mr. Albert Gallatin, who, of all American students, has made himself most thoroughly acquainted with what remains of the historical elements of the Nahuatl and Maya people, has brought together the results of his investigations in a lecture published in the “Transactions of the American Ethnological Society,” New York, 1858, vol. I., pages 104–114. The information therein contained attests an entire familiarity with the method pursued by Señor Perez in his commentary, without, indeed, undertaking any severe criticism of it. In our opinion Mr. John L. Stephens and Mr. Gallatin are the only Americans who have recognized Señor Perez’s merits in an unequivocal manner, and have brought them to the knowledge of the world.