On October 31, 1887, he celebrated the seventieth anniversary of his birth. His disciples and friends made it the occasion for an extraordinary ovation, and from all countries and climes homage was laid at his feet. An overwhelming number of addresses, gifts, congratulatory letters, and poems proved that his achievements were in the mind and his honor in the keeping of the whole body of intelligent Jews. A particularly gratifying surprise came in the shape of a diploma announcing that on October 27, 1888, he, the Jew, who had not dealt leniently with the Spanish nation in his historical writings, had been elected an honorary member of its section in history by the Spanish Academy at Madrid. Until the very last his body and mind retained remarkable elasticity and vigor; time seemed to pass him by unnoticed. His indestructible working powers and his literary fertility continued to be astonishing.[83] Even after concentrating his efforts on exegetical research, he was a vigilant reader of the monographs in whatever civilized language, bearing, however remotely, on problems of the science of Judaism. He gave the conclusions reached in them a critical examination, and either noted them for the enrichment and correction of a new edition of his “History,” or refuted them in special articles, if they seemed sufficiently important. For, besides his historical and exegetical works, in number and bulk an imposing array, he published numberless essays and _Programmschriften_ on the most various subjects, many of them real gems, models of clear writing and deep scholarship. In some of them daring theories are advanced, as, for instance, the one which he would never abandon, that the Massora originated with the Karaites, from whose literary works the Rabbanites derived it. The conjecture was received with a great display of indignation, but its refutation was not equally emphatic, and it cannot be denied that certain evidences may be interpreted in its favor. Among his _Programmschriften_ the following deserve to be singled out: “Visigothic Legislation with Regard to the Jews,”[84] in the annual report of the Jewish Theological Seminary for 1858; “Frank and the Frankists,”[85] in that for 1868; and “The Kingdom of Mesene and its Jewish Population,”[86] in that for 1879. In the _Monatsschrift für Geschichte und Wissenschaft des Judenthums_, of which, as mentioned above, he was the editor from 1869, the greater part of the articles issued from his pen. There is but one way of accounting for his numerous achievements: he understood to perfection the art of utilizing every moment.