of paper, ladies’ fancy work, &c.—Thread marble is given by first covering the edge uniformly of one colour, then laying pieces of thick thread irregularly on different parts of it, and giving it a fine dark sprinkle. When well managed the effect is very pleasing.—Rice marble is given in a similar way to the last by using rice.—Tree marble is done on leather book-covers, &c., by bending the board a little in the centre, and running the marbling liquid over it in the form of vegetation. The knots are given by rubbing the end of a candle on those parts of the cover.—Wax marble is given in a similar way to thread marble, but using melted wax, which is removed after the book is sprinkled and dried; or a sponge charged with blue, green, or red may be passed over. This, also, is much used for stationery work, especially for folios and quartos. The ‘vinegar black’ of the bookbinders is merely a solution of acetate of iron, made by steeping a few rusty nails or some iron filings in vinegar. All the ordinary liquid colours that do not contain strong acids or alkalies may be used, either alone or thickened with a little gum, for marbling or sprinkling books.
Sprinkling is performed by simply dipping a stiff-haired painter’s brush into the colour, and suddenly striking it against a small stick held in the left hand over the work. By this means the colour is evenly scattered without producing ‘blurs’ or ‘blots.’
Paper, PASTEBOARD, &c., in sheets, are marbled and sprinkled in a similar manner to that above described, but in this case the gum trough must, of course, be longer.
MARGAR′IC ACID. This term was formerly applied to a mixture of palmitic and stearic acids, produced by decomposing the alkaline soaps of solid fats with an acid, but it is now given to a fatty acid which can only be obtained artificially.
MAR′GARIN. Syn. Margarate of glyceryl. A constituent formerly supposed to exist in solid fats, but now regarded as a mixture of stearin and palmitin.
MARINE′ ACID. See Hydrochloric acid.
MARL. A natural mixture of clay and chalk, with sand. It is characterised by effervescing with acids. According to the predominance of one or other of its component parts, it is called argillaceous, calcareous, or sandy marl. It is very generally employed as a manure for sandy soils, more particularly in Norfolk. See Soils.
MAR′MALADE. Originally a conserve made of quinces and sugar; now commonly applied to the conserves of other fruit, more especially to those of oranges and lemons.
Prep. Marmalades are made either by pounding the pulped fruit in a mortar with an equal or a rather larger quantity of powdered white sugar, or by mixing them together by heat, passing them through a hair sieve whilst hot, and then putting them into pots or glasses. The fruit-pulps are obtained
by rubbing the fruit through a fine hair sieve, either at once or after it has been softened by simmering it for a short time along with a little water. When heat is employed in mixing the ingredients, the evaporation should be continued until the marmalade ‘jellies’ on cooling. See Conserves, Confections, Electuaries, Jams, Jellies, and below.