_Mercury_--“eloquent and inventive ... slender of figure, tall and well grown, with delicate lips. Quicksilver is his metal”--sets forth various applications of the arts and sciences. Especially interesting is the goldsmith’s shop at the left, where we see an engraver actually at work upon a plate. The goldsmith is seated, his apprentice behind him, as a prospective purchaser examines a richly ornamented vessel. In the foreground a sculptor is chiseling his statue, while, standing above, on a scaffolding, a fresco painter is actively at work--a record of the Florence of 1460 or thereabouts, full of interest for us. [Illustration: ANONYMOUS FLORENTINE, XV CENTURY. MERCURY Size of the original engraving, 12¾ × 8½ inches In the British Museum] [Illustration: ANONYMOUS FLORENTINE, XV CENTURY. LADY WITH A UNICORN Size of the original engraving, 6¼ inches in diameter In the British Museum] To a slightly later date, 1465-1470, belong the group of Fine Manner prints, known as the OTTO PRINTS, also emanating from the Finiguerra workshop. They are not a series, in any true sense, and owe their name--also their fortunate preservation--to the accidental circumstance of their having belonged at one time to Peter Ernst Otto, a merchant and collector of Leipzig. The purpose served by these prints--twenty-four in all--was the decoration of box lids, either as patterns to be copied, in the case of metal caskets, or to be colored and pasted on the lids of wooden boxes. The escutcheons are usually left blank, to be filled in by hand with the device of the donor or the recipient, or with some appropriate sentiment. In the print entitled _Two Heads in Medallions and Two Hunting Scenes_ we again meet with the animal motives taken from the Picture-Chronicle. One of the most charming is the _Lady with a Unicorn_ (Chastity), in its arrangement suggestive of the beautiful drawing by Leonardo da Vinci in the British Museum; and its symbolic meaning is doubtless the same. “The unicorn,” writes Leonardo in his “Bestiarius,” “is distinguished for lack of moderation and self-control. His passionate love of young women makes him entirely forget his shyness and ferocity. Oblivious of all dangers, he comes straight to the seated maiden and falling asleep in her lap is then caught by the hunter.” The ermine, likewise a sign of chastity, is to be seen at the right, gazing upward into Marietta’s face.