From his varied talents and the excellence which he displayed in every branch of art that he attempted, Albert Durer is entitled to rank with the most extraordinary men of his age. As a painter he may be considered as the father of the German school; while for his fidelity in copying nature and the beauty of his colours he may bear a comparison with most of the Italian artists of his own age. As an engraver on copper he greatly excelled all who preceded him; and it is highly questionable if any artist since his time, except Rembrandt, has painted so many good pictures and engraved so many good copper-plates. But besides excelling as an engraver on copper after the manner in which the art had been previously practised, giving to his subjects a breadth of light and a depth of shade which is not to be found in the productions of the earlier masters, he further improved the art by the invention of etching,[V-35] which enables the artist to work with greater freedom and to give a variety and an effect to his subjects, more especially landscapes, which are utterly unattainable by means of the graver alone. [Footnote V-35: In the process of etching the plate is first covered with a resinous composition--called etching ground--on which the lines intended to be _etched_, or bit into the plate, are drawn through to the surface of the metal by means of a small pointed tool called an etching needle, or an etching point. When the drawing of the subject upon the etching ground is finished, the plate is surrounded with a slightly raised border, or “wall,” as it is technically termed, formed of rosin, bee’s-wax, and lard; and, a corrosive liquid being poured upon the plate, the lines are “bit” into the copper or steel. When the engraver thinks that the lines are corroded to a sufficient depth, he pours off the liquid, cleans the plate by means of turpentine, and proceeds to finish his work with the graver and dry-point. According to the practice of modern engravers, where several _tints_ are required, as is most frequently the case, the process of “biting-in” is repeated; the corrosive liquid being again poured on the plate to corrode deeper the stronger lines, while the more delicate are “stopped out,”--that is, covered with a kind of varnish that soon hardens, to preserve them from further corrosion. Most of our best engravers now use a diamond point in etching. _Nitrous_ acid is used for “biting-in” on copper in the proportion of one part acid to four parts water, and the mixture is considered to be better after it has been once or twice used. Before using the acid it is advisable to take the stopper out of the bottle for twenty-four hours in order to allow a portion of the strength to evaporate. During the process of biting-in a large copper-plate the fumes which arise are so powerful as frequently to cause an unpleasant