(see that article, Encycl. and Vegetable Stories, Suppl.) are so often adulterated with minerals prejudicial to the health, that various methods have been devised for detecting the adulteration. The property which liver of sulphur (alkaline sulphures) and hepatic air (sulphurated hydrogen) possess of precipitating lead in a black form, has been long ago made public; and this property has been employed to determine the quality of wines by means of the liquor probatorius Wirtembergensis, or Wirtemberg proving liquor. But in trying wines supposed to have been adulterated, this proof does more hurt than service, because it precipitates iron of the same colour as the pernicious lead. Many wine merchants, therefore, of the greatest respectability, rendered by these means suspected, have been ruined.
The following is recommended by M. Hanhemann as a better test of sound wines than the proving liquor of Wirtemberg. Mix equal parts of oyster shells and crude sulphur in a fine powder, and put the mixture into a crucible. Heat it in a wind furnace; and increase the fire suddenly, so as to bring the crucible to a white heat, for the space of 15 minutes. Pulverise the mass when it is cool, and preserve it in a bottle closely stoppered.
To prepare the liquor, put 120 grains of this powder, and 120 grains of cream of tartar (acidulous tartrate of potash), into a strong bottle; fill the bottle with common water, which boil for an hour, and then let it cool; close the bottle immediately, and shake it for some time: after it has remained at rest to settle, decant the pure liquor, and pour it into small phials capable of holding about an ounce each, first putting into each of them 20 drops of muriatic acid. They must be stoppered very closely with a piece of wax, in which there is a small mixture of turpentine.
One part of this liquor, mixed with three parts of suspected wine, will discover, by a very sensible black precipitate, the least traces of lead, copper, &c., but will produce no effect upon iron, if it contains any of that metal. When the precipitate has fallen down, it may still be discovered whether the wine contains iron, by saturating the decanted liquor with a little salt of tartar (tartarous acidulum of potash), by which the liquor will immediately become black. Pure wines remain clear and bright after this liquor has been added to them.
WOODCUTS are engravings on wood, commonly on box, which, in many cases, are used with advantage instead of copper-plates. The art of cutting or engraving on wood is undoubtedly of high antiquity; for Chinese printing is a specimen of it. (See CHINA, n° 127, Encycl.) Even in Europe, if credit be due to Papillon, this art was practised at a period considerably remote; for he mentions eight engravings on wood, entitled, "A representation of the warlike actions of the great and magnanimous Macedonian king, the bold and valiant Alexander; dedicated, presented, and humbly offered, to the most holy father, Pope Honorius IV. by us Alexander Alberic Cunio Chevalier, and Isabella Cunio, &c." This anecdote, if true, carries the art of cutting in wood back to 1284 or 1285; for Honorius occupied the papal throne only during these two years. Even this is not the remotest period to which some have carried the art in Europe; for the use of seals or figures being of very high antiquity, they imagine that the invention of wood-cuts must be coeval with them. The supposition is certainly plausible, but it is not supported by proof. The earliest impression of a woodcut, of which we have any certain account, is that of St Christopher carrying an infant Jesus through the sea, in which a hermit is seen holding up a lantern to show him the way; and a peasant, with a sack on his back, climbing a hill, is exhibited in the background. The date of this impression is 1423.
In the year 1430 was printed at Haarlem, "The history of St John the evangelist and his revelation, represented in 48 figures in wood, by Lowrent Janzon Collet;" and, in 1448, Jorg Schappf of Augsburg cut in wood the history of the Apocalypse, and what was called The poor man's bible. (See ENGRAVING, Encycl. page 668.)
A folio chronicle, published 1493 by Schedel, was adorned with a vast number of wood-cuts by William Plydenwurff and Michael Wolgemut, whose engravings were greatly superior to any thing of the kind which had appeared before them. Wolgemut was the preceptor of Albert Durer, whose admirable performances in this department of art are justly held in the highest esteem even at the present day.
About this period it became the practice of almost all the German engravers on copper to engrave likewise on wood; and many of their wood-cuts surpass in beauty the impressions of their copper-plates. Such are the wood-cuts of Albert Aldtorter, Hifhel Pen, Virgil Solis, Lucas van Cranach, and Lucas van Lyden, the friend and imitator of Albert Durer, with several others.
It appears that the Germans carried this art to a great degree of perfection. Hans or John Holbein, who flourished in 1500, engraved the Dance of Death, in a series of wooden-cuts, which, for the freedom and delicacy of execution, has hardly been equaled, and never surpassed.
Italy, France, and Holland, have produced many capital artists of this kind. Joan Torstenson printed a bible at Lyden, in 1554 (a copy of which we have seen), with wooden-cuts of excellent workmanship. Christopher Jegher of Antwerp, from his eminence in the art, was employed by Rubens to work under his inspection. Wood-cuts inspection, and he executed several pieces which are held in much estimation; the character of these is boldness and spirit.
The next attempt at improvement in this art was by Hugo da Carpi, to whom is attributed the invention of the chiaro scuro. Carpi was an Italian, and of the 16th century; but the Germans claim the invention also, and produce in evidence several engravings by Mair, a disciple of Martin Schoen, of date 1499. His mode of performing this was very simple. He first engraved the subject upon copper, and finished it as much as the artists of his time usually did. He then prepared a block of wood, upon which he cut out the extreme lights, and then impressed it upon the print; by which means a faint tint was added to all the rest of the piece, excepting only in those parts where the lights were meant to predominate, which appear on the specimens extant to be whitened with white paint. The drawings for this species of engraving were made on tinted paper with a pen, and the lights were drawn upon the paper with white paint.
There is, however, a material difference between the chiaro scuro of the old German masters and those of the Italians. Mair and Cranach engraved the outlines and deep shadows upon copper. The impression taken in this state was tinted over by means of a single block of wood, with those parts hollowed out which were designed to be left white upon the print. On the contrary, the mode of engraving by Hugo da Carpi was, to cut the outline on one block of wood, the dark shadows upon a second, and the light shadows, or half tint, upon a third. The first being impressed upon the paper, the outlines only appeared; this block being taken away, the second was put in its place, and being also impressed on the paper, the dark shadows were added to the outlines; and the third block being put in the same place upon the removal of the second, and also impressed upon the paper, made the dim tints, when the print was completed. In some instances, the number of blocks were increased, but the operation was still the same, the print receiving an impression from every block.
In 1668, John Baptist Michel Papillon practised engraving on wood with much success, particularly in ornamental foliage and flowers, shells, &c. In the opinion, however, of some of the most eminent artists, his performances are stiff and cramped. From that period the art of engraving on wood gradually degenerated, and may be said to have been wholly lost, when it was lately re-invented by Mr Bewick of Newcastle.
This eminent artist was apprentice to Mr Biebly, an engraver on metal of the very lowest order, who was seldom employed in anything more difficult than the cutting of the face of a clock. Application having been made to this man for a wood-cut or two of the most trifling description, the job was given to Thomas Bewick; by whom it was executed in such a manner,
Suppl. Vol. II. Part II.
(a) The designs were by Thornton; and the cuts from them have been compared to Holbein's far-famed Dance of Death.
(b) Mr Nefsoi has indeed introduced something of it into two or three of his pieces, merely to show that he could do it; but so great was the labour, and so little the advantage of this improvement, if such it can be called, that probably it will not be attempted again. Wood-cuts in pieces of the proper thickness. As wood-cuts are generally employed in the printer's press amidst a form of types, this thickness must be regulated by the height of the types with which they are to be used. The tools employed are nearly the same with those used in copperplate engraving, being only a little more deep, or lozenge, as engravers call it. They must have points of various degrees of fineness for the different purposes to which they are applied, some of them being too much rounded off at the bottom as to approach to the nature of a good edge, whilst others are in fact little chisels of various sizes. These chisels and gouges, to which every artist gives the shape which he deems most convenient, are held in the hand in a manner somewhat different from the tool of the engraver on copper, it being necessary to have the power of lifting the chips upwards with ease. To attempt a description of this in writing would be in vain; but it is easily acquired, we are told, by practice.
The pupils of the school of Bewick consider it as quite improper to speak of his invention as a revival of the ancient art. Some old prints, it is true, have the appearance of being executed in the same way with his; but others have certainly been done by a method very different. It is therefore not fair to appreciate the present art by what has been done, but by what may be done; and that remains yet to be shown. The art is in its infancy; and those who are disposed to compare it with the art of engraving on copper, ought to look back to the period when copperplate engraving was of as recent invention as Bewick's method of engraving on wood. Marc Antonio, who engraved under the direction of the great painter Raphael, thought it no mean proof of his proficiency in his art, that he was able to imitate on copper plates the wood-cuts of Albert Dürer; and Papillon is highly indignant that there should have been persons so blind as to mistake the copies for the originals. If copper has its advantages over wood in point of delicacy and minute-ness, wood has, in its turn, advantages not inferior in regard to strength and richness. Those prints which were executed under the auspices of Titian and Rubens, will always remain a monument of the spirit and vigour natural to wood-engraving; and if there be not found in them all the attention to chiaro scuro, which the present age demands, it must not be attributed either to defect in the art, or to want of abilities in the artists, but to the taste of the times when chiaro scuro was little understood. It remains for some enterprising artist to show that the vigour of the ancient art may be attained by the present one, and at the same time to add to that vigour those gradations of shade which are so much admired in good copperplates. As there seems to be a more perfect, or at least a more pleasant black produced by wood than by copperplate printing, and certainly a more perfect white (c), who will say that any intermediate shade whatever may not be produced by wood-cuts? To attempt this on a small scale would indeed be vain, because the slightest variation, produced by a little more or less ink, or a harder pressure in printing, bears such a proportion to a very short line, as must necessarily render the attempt abortive.
(c) The parts of the print intended to be white are not even touched by the wood-block. operation opens the wool, and makes it connect together into a rough sliver, but does not clear it. The clearing is performed by the second, and, if necessary, a third operation. A set of machinery, consisting of three machines, will require the attendance of an overlooker and ten children, and will comb a pack, or 240 lb. in twelve hours. As neither fire nor oil is necessary for machine-combing, the saving of those articles, even the fire alone, will, in general, pay the wages of the overlooker and children; so that the actual saving to the manufacturer is the whole of what the combing costs, by the old imperfect mode of hand-combing. Machine-combed wool is better, especially for machine-spinning, by at least 12 per cent. being all equally mixed, and the slivers uniform, and of any required length.
Z.