Valuable Secrets concerning Arts and Trades:
or Approved Directions, from the best Artists, for the Various Methods...
Printed by Thomas Hubbard,
Norwich, 1795Chap. V. Secrets concerning colours & painting.
§ VIII. Preparations of colours of all sorts for oil, water, and crayons.
1. Have a glazed pipkin, quite new, holding fully two English quarts. Wash it with boiling water, then fill it with spring or river water, very clean and filtered. Set it on blasting coals, and when it begins to boil throw in a drachm of chouan in fine powder, which you boil very quick for near a quarter of an hour. Then strain this water through a cloth washed in lye, and not with any soap, and receive it in another new glazed pipkin, cleaned and washed as the first. Put this on a fire, not quite so blasting as the first; and, when it be gins to give signs of boiling, throw in one ounce of the finest cochineal, pulverised very fine. Stir often with a little hazel-tree stick, stripped of its peal, and let boil gently for near a quarter of an hour; then throw in sixty grains of autour, in subtile powder, and keep it on the same degree of fire, boiling for half a quarter of an hour. Take it off from the fire, and throw in sixteen grains of Roman alum in powder, then drain it immediately through a clean cloth, washed with lye, and no soap, and receive it in two different large china bowls, capable to contain more than three pints of liquor a-piece, new and perfectly clean. Place these in a room, where they will be perfectly free from dust, and let them rest there for a week, that the carmine may have time to make a precipitation.
2. At the end of this term, decant oat gently your tincture into two other China bowls, of the same size as the two former, & as perfectly clean, taking great care in decanting, to do it so gently that the liquor may not carry the carmine along with it. Then letting dry in a shade the carmine, which shall have been left in the bottom of your bowls, gather it with a little brush, and keep it very cleanly.
3. Eight or ten days afterwards, more or less, decant again the tincture which is in the second bowls, inro a new varnished pipkin, then dry and gather the carmine, which is at the bottom, in the same manner as the first.
4. Then set the pipkin, in which the carmine has been decanted for this second time, on the fire, and vaporise the liquor gently, till the ground remains in the consistence of a pap. This pap-like ground must then be put into several small china cups, and place in the sun to dry, which will procure you again another carmine darker, and much less valuable than the first. Should there happen any moistness on your last cups, take it off immediately, but gently, and with a great deal of care,
5. In order to take the water off from your china bowls, you might make use of another method, viz. a very fine and clean sponge, in the following manner. Dip your sponge into very clear and pure water, and there work it well with your hand, soaking and preising it alternately till you have rendered it very soft. Then press and squeeze it quite dry in a clean towel. Now, if you only approach it to the superfice of the tinctured water, it will immediately fill itself with it, and you may squeeze it into another empty bowl, thus repeating the same process, till you have got it all out of the first bowls; taking care every time you approach it to the surface of the water, left it should touch the carmine; for no doubt but it would carry some along with the water.
6. If you dissolve one drachm of mineral crystal into this tincture, by boiling it to that effect for five or six minutes, it will help a great deal the precipitation of the colour, from which you takeout afterwards the water with a sponge, as we said before. Should the water you have thus drawn out be still tinged, you may add some more mineral crystal to it again; boil it as before, strain it through a cloth, and let it settle. By these means you will have very fine crimson carmine.
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