| Wax | 16 | parts. |
| Tallow | 6 | — |
| Hard tallow soap | 6 | — |
| Shell-lac | 12 | — |
| Mastic in tears | 8 | — |
| Venice turpentine | 1 | — |
| Lamp black | 4 | — |
The mastic and lac, previously ground together, are to be heated with care in the turpentine; the wax and tallow are to be added after they are taken off the fire, and when their solution is effected, the soap shavings are to be thrown in. Lastly, the lamp black is to be well intermixed. Whenever the union is accomplished by heat, the operation is finished; the liquor is left to cool a little, then poured out on tables, and, when cold, cut into square rods.
Lithographic ink of good quality ought to be susceptible of forming an emulsion so attenuated, that it may appear to be dissolved when rubbed upon a hard body in distilled or river water. It should be flowing in the pen, not spreading on the stone; capable of forming delicate traces, and very black to show its delineations. The most essential quality of the ink is to sink well into the stone, so as to re-produce the most delicate outlines of the drawing, and to afford a great many impressions. It must therefore be able to resist the acid with which the stone is moistened in the preparation, without letting any of its greasy matter escape.
M. de Lasteyrie states that after having tried a great many combinations, he gives the preference to the following:—
| Tallow soap, dried | 30 | parts. |
| Mastic, in tears | 30 | — |
| White soda of commerce | 30 | — |
| Shell-lac | 150 | — |
| Lamp black | 12 | — |
The soap is first put into the goblet and melted over the fire, to which the lac being added fuses immediately; the soda is then introduced, and next the mastic, stirring all the while with a spatula. A brisk fire is applied till all these materials be melted completely, when the whole is poured out into the mould.
The inks now prescribed may be employed equally with the pen and the hair pencil, for writings, black-lead drawings, aqua tinta, mixed drawings, those which represent engravings on wood (wood cuts), &c. When the ink is to be used it is to be rubbed down with water, in the manner of China ink, till the shade be of the requisite depth. The temperature of the place ought to be from 84° to 90° Fahr., or the saucer in which the ink-stick is rubbed should be set in a heated plate. No more ink should be dissolved than is to be used at the time, for it rarely keeps in the liquid state for 24 hours; and it should be covered or corked up.
Autographic paper.—Autography, or the operation by which a writing or a drawing is transferred from paper to stone, presents not merely a means of abridging labour, but also that of reverting the writings or drawings into the direction in which they were traced, whilst, if executed directly upon the stone, the impression given by it is inverted. Hence, a writing upon stone must be inverted from right to left to obtain direct impressions. But the art of writing thus is tedious and difficult to acquire, while, by means of the autographic paper and the transfer, proofs are obtained in the same direction with the writing and drawing.
Autographic ink.—It must be fatter and softer than that applied directly to the stone, so that though dry upon the paper, it may still preserve sufficient viscidity to stick to the stone by mere pressure.
To compose this ink, we take—