AULUS GELLIUS, author of “Attic Nights” (Noctes Atticæ) lived in the second century of the Christian era between dates which are not accurately established. The date of his death is fixed approximately at 180 A.D., but even his birthplace is unknown and of his life there is little to be said with certainty, except that he lived at Rome and kept a “Commonplace Book,” in which he wrote down his own thoughts and the thoughts of others as he gathered them from conversations. These entries formed the basis of his “Attic Nights,”—a work to which some object on the ground that “it is utterly devoid of sequence and arrangement.” This is really a merit, however, for the book is essentially a collection of essays, one of the earliest suggestions of what was to become the essay writing of modern times. Its separate chapters are really distinct essays or “Pensées” on an extraordinary variety of subjects, interspersed with anecdotes, and frequently varied by attempts at philological or scientific definitions and analyses. Gellius had an active and inquiring mind which counted “nothing human foreign.” The twenty books of his “Attic Nights” touch on almost every subject which exercised the cultivated intellect of his time.