their greens by the mixture of blue and yellow, and by varying these, a vast variety of green tints are obtained.

104. Sap-green is the concreted juice of the buckthorn berries. It is used only in water, and is employed chiefly in flower-painting, colouring prints,

&c.

105. Verdigris is an imperfect oxyd of copper, combined with a small portion of acetic, carbonic acid, and water.

It is prepared in large quantities, chiefly in France near Montpellier, by stratifying copper-plates with the husks of grapes, yet under various fermentation, which soon grow, acid, and corrode the copper. After the plates have stood in this situation for a sufficient time, they are moistened with water, and exposed in heaps to the air. The verdigris is scraped off from their surface as it forms.

Verdigris is of a bluish-green colour, it has no body, does not stand, and is only used for coarse purposes; it answers best in varnishes.

106. Distilled verdigris, sometimes called crystils verdigris, is prepared from common verdigris, by dissolving it in vinegar. It is of very bright green, and is used chiefly for varnishes, and in colouring maps, &c.

Brown Colours.

107. Bistre is the finer part extracted from the soot of burnt wood. It is used alone for sketches in water-colours, being a transparent warm colour.

108. Roman-bistre is a very excellent but scarce kind of bistre imported from Rome.

109. Cologne-earth, a mineral substance of a darkblackish brown colour, is a very useful pigment; what is generally sold in the shops for Cologne-earth is an artificial mixture.

110. Raw-umbre, a native ochreous earth, of a light-brown, stands well.

111. Burnt-umbre is only the last mentioned colour, calcined in the fire. It then acquires a rich deep brown, and is of great use, being a fine colour, that stands well.

112. Asphaltum, used in oil, is of a very rich deep brown. It is a transparent or glazing colour that will not work in water, but, when dissolved in turpentine, it becomes a useful substance for giving deep and spirited touches to drawings. The linens in which the Egyptians wrapped their mummies were dipped in Asphaltum.

White Colours.

113. Flake-white is an oxyd of lead, formed by corroding lead with vegetable acids, or vinegar.

114. White-lead is the same as flake white, but of an inferior quality. It is the only white used in oilpainting, and is therefore a very useful colour; in water it always turns black.

115. Egg-shell white, and oyster-shell white, are only egg-shells or oyster shells calcined; the animal gluten is thus destroyed, leaving the lime behind, which soon attracts the carbonic acid again from the atmosphere. Well washed Spanish-white, or common whitening, answers the same purpose.

116. Permanent-white is a white sold in the shops under this name, and it will not change; but great care must be employed in using it, as it is made from barytes, a deadly poison.

Black Colours.

117. Lamp-black, the soot of oil, collected after it is formed by burning, is very generally used, both in oil and water, and stands perfectly well. Ivoryblack, the charcoal of ivory or bone, formed by giving them a great heat, while they are deprived of all access of air. It is used both in oil and water. Blue-black, the coal from burning vine-stalks in a close vessel, is like ivory black with a tint of blue.

CHAPTER III.

PRINTING, THE MAKING OF INK AND PAPER.

SECTION I.

STEREOTYPE PRINTING.

118. STEREOTYPE PRINTING was certainly anterior to printing by moveable types. The method of printing linen and paper for hangings, has been practised in the East from time immemorial. Printing from wooden blocks has been known in China for more than 1600 years. When a work is to be stereotyped, it is fairly transcribed upon a thin, transparent paper. Each leaf is then reversed, and fixed upon a smooth block of hard wood, where the characters are engraven in relief; there is therefore a separate block for each page. The Italians, Germans, Flemings, and Dutch, began to engrave on wood and copper, about the end of the fourteenth century, and inscriptions in relief upon monuments and altars, in cloisters, and over church porches, became models for block-printing; and the letters upon painted windows, strongly resemble those in books of images.

The invention of cards in France, in the reign of Charles the Wise, about the year 1376, was an intermediate step. They were soon introduced into Spain, Italy, Germany, and England. At first the cards were painted; afterwards, about the year 1400, a method was devised of printing them from blocks, and to this we may trace the art of printing. The next step resulted the books of images, printed from wooden blocks; one side of the leaf only was impressed, the corresponding text was placed below, at the side, or it issued from the mouth of the figure; the idea of stereotype printing is, therefore, not of modern origin.

Towards the close of the seventeenth century, this art, therefore, was practised in Holland. William Ged, of Edinburgh, in the year 1725 made the first use of this art in Britain; but, owing to some defect in the plan, or want of skill in its execution, the invention attracted little notice.

In 1782, my friend Mr. Tilloch revived, or rather re-discovered this art; he was ignorant of Ged's contrivance long after he had announced his own. In the subsequent year, he took out a patent for it, in conjunction with Foulis, of Glasgow.

About 1789, M. Didot, of Paris, stereotyped his logarithmic tables; and several improvements, which he introduced, rendered his mode both convenient and useful. The French, who would be foremost in every thing, claim the merit of this invention. The name stereotype seems first to have been employed by M. Didot; it is derived from legos, solidus, and TUTOS, typus, denoting that the types were soldered, or otherwise connected together; but does it follow that the French have the honour of this invention?

After Tilloch had given up the prosecution of this art, Wilson, a printer, of London, engaged with the late Earl Stanhope, to bring it to perfection, and eventually established it in this country. After two years application, the stereotype art was, with the approbation of Earl Stanhope, offered to the University of Cambridge, and accepted by them [1804]. Their bibles, testaments, and prayer-books being printed in this manner, and the plan has been followed by the Bible Society, and other persons, for printing bibles, dictionaries, grammars, &c. &c. The stereotype method has the advantage of common printing, wherein no alteration, as to plan or size, takes place. But for general purposes in the art, the method by moveable types is incontestably the best.

The method of Stereotype Printing is this: A page is composed, in the common way, with moveable types; and when it has been corrected, a mould, or impression, is then taken off the page with plaster of Paris, from which one in metal is cast. Ged's plan, consisted only in setting up the moveable types, and soldering them together, to form a permanent page. The principal objects of this invention are correctness and economy.

Letter-press Printing.

119. Printing by letter-press, the most curious branch of the art, demands particular notice, as three cities in Europe, Haerlem, Strasbourg, and Mentz, claim the honour of this invention. A person named Guttemberg appears to have been the inventor of the art of printing by moveable types; he began the art at Strasbourg, and perfected it at Mentz.

The evidence in favour of Guttemberg appears decisive: we shall not enter into any examination of the claims advanced by John Fust, of Mentz; John Mental, of Strasbourg; and L. John Koster, of Haerlem. When Mentz was taken by Adolphus, Count of Nassau, in 1462, Fust, and Schoeffer his servant and son-in-law, suffered materially with their fellow townsmen. Their workmen dispersed to seek their fortunes, and thus the art was diffused over Europe. When it was first established at Paris, the transcribers of books, finding their trade injured, presented a memorial of complaint to the parliament, and that tribunal, as superstitious as the people, who took the printers for conjurors, had their books seized and confiscated. But Louis XI. forbade the parliament to take any farther cognizance of the affair, and restored their property to the printers.

The art of printing now spread itself with astonishing rapidity, over a great part of Europe. It was practised at Rome in 1467, and the year following Thomas Bouchier, Archbishop of Canterbury, introduced it into England. But both the origin and the history of the first introduction of the art of printing into this country, are involved in doubt and obscurity.

Fine printing was first introduced by Baskerville, and the numerous editions which he published of various important works, but particularly of the Latin classics, are well known. They were printed in a style surpassing every thing of the kind which had been issued from the press; and the peculiar excellence attached to the types of Baskerville, and the consequent celebrity he obtained, gave a stimulus to the exertions, and have called forth the emulation of Bensley, Bulmer, Davison, Whittingham, M'Creery, Ballantyne, and Ramsey, who have produced the finest specimens of typography that are to be found in Europe.

120. Types are the letters of the alphabet, &c. divided into LARGE CAPITALS, SMALL CAPITALS, and Italic. The letters most frequently used are: Black Letter, Great Primer, English, Pica, Small Pica, Long Primer, Bourgeois, Brevier, Minion, Nonpareil, Pearl, and Diamond.

BLACK LETTER.

Mode of Letter-press Printing.

GREAT PRIMER.

The workmen employed in this