Various were the materials upon which he first essayed to complete his purposes; till, at length, chance directed him to try what could be effected upon stone. For this purpose, he used a species found in Germany, of a beautifully close grained and dense kind, susceptible of receiving a fine polish, called Kellheim stone. Knowing the failures which his countrymen had experienced in endeavouring to fix the ink in this stone for etching, he had recourse to a chemical experiment to obviate this, which succeeded in the following manner:--To four or five parts of water, he added one of rectified vitriol, which instantly produced an effervescence, on being poured upon it; the stone was instantly covered with a coat of gypsum, which to vitriol is impenetrable; this is easily wiped off, and the stone being dried, it is ready for use. The next want he found, was a species of ink, proper to answer the peculiar purposes of the material whereon he had to operate; for which he discovered none so well adapted as the following mixture:--A composition of three parts of wax, with one of yellow soap, is melted over a fire, and mixed with a small portion of lamp-black, dissolved in rain-water. But this is now greatly simplified, as the lithographic printers generally use the same ink as the copperplate printers. The process of lithography is very simple. The article wanted to be printed is written or drawn upon a piece of transfer paper, which being wet and laid on the stone, and put through the press, the writing or drawing remains on the stone, and any number of impressions may be taken off. Care must be taken, before inking, to come over the stone with a damp sponge, to prevent the ink adhering to the places not wanted, which it would otherwise do. We understand the Bath and Portland stone is successfully used; but the best yet found in Britain, for the purpose, is what is known by the name of _lias_, raised near Stratford-on-Avon, in Warwickshire; it is a calcareous and partly siliceous stone, and we think not destitute of magnesia, having, when, polished, a very silky and somewhat saponaceous feel. This art has flourished to a greater extent than we believe the most sanguine expectations of its inventor could have anticipated. Many beautiful specimens of art have been produced equal to the finest copper-plate engravings. It is excellently adapted for drawing of plans, bill-heads, circulars, cards, and many other light articles, which used formerly to be printed by means of letter-press; and on account of the numerous ornaments so easily applied to the lithographic process, the most of these, and similar articles, are principally lithographed, to the detriment, we would conceive, of the letter-press and copper-plate printers. PAPER.