CHAP. (II. ./UCiLANUA'L'K.i:. /UHLANS. 1429 



to express an oil from it, which is employed by artists in mixing white, or any 

 delicate colours; and which serves as a substitute for olive oil in the kitchen 

 and at table, for oil of almonds in medicine, and for burning in lamps. Half 

 the people in France, Bosc observes, consume no other oil than that of the 

 walnut. The marc, or mass of husks which remains after the oil is extracted, 

 is used to feed swine or sheep, or is formed into cukes, and serves for the 

 nourishment of poultry; and the inhabitants of the Mirbalais make a kind of 

 candles of it, which burn with a very clear flame. In Tartary, Dr. Clarke 

 informs us, an incision is made in the tree in spring, when the sap is rising, 

 and a spigot inserted for some time ; after which, on withdrawing it, a clear 

 sweet liquor flows out, which, when coagulated by evaporation, is used as 

 sugar. In other parts of Europe and Asia, a wine is made of the sap, or 

 a spirit distilled from it. The roots of the walnut, before the rising of the sap, 

 yield, by boiling, a dark brown dye, which becomes fixed, in wood, hair, or 

 wool, without the aid of alum. This dye is used by gipsies, and also by 

 theatrical performers, to stain the skin of a deep brown. The husk of the 

 nut produces nearly the same colour as the root, and also the bark of the 

 young shoots, and even the leaves. For this purpose, the bark should be 

 taken oft' when the sap is in movement in spring ; the leaves should be gathered 

 when the nuts are half formed; and the husks of the nuts when the fruit is 

 nearly ripe, or after its maturity, when they begin to scale off. The husk of 

 the nuts is used by cabinet-makers and joiners, to stain white wood and yellow 

 wood of a dark brown or black colour, like that of the walnut. When the 

 fingers are stained with walnut juice, or the skin has been dyed with it, it is 

 exceedingly difficult to remove; but this may be partially effected by the 

 application of moistened salt. 



To obtain a dark.brown or Mack Dye from the Walnut, the husks must be left to rot, or to 

 macerate, in a heap in the shade, taking care to keep them always moist. When they are sufficiently 

 rotted and black, they are then boiled, adding to them fresh water, and supplying them with a 

 sufficient quantity of it This gives a most beautiful nut colour to any kind of wood, which may.be 

 made lighter or darker, as may be wished, by employing a greater or less quantity of husks to the 

 same quantity of water ; or the wood may veined by applying the colour with a pencil to particular 

 parts ; after which it is varnished. When it is wished to colour the boarded floor of an apartment, 

 the husks are boiled, and no more water added than is sufficient to keep the bottom of the vessel 

 from being injured by the fire. When the whole is reduced to one mass, it is laid on the boards, 

 and left to dry; it is then swept off, and the wood rubbed with hard, short-bristled brushes, till it 

 becomes perfectly bright. 



To extract the Oil of Walnuts. When the fruit is gathered, and the nuts are separated from the 

 husks, they should be kept dry, and occasionally moved till they are used. The most proper time 

 for the operation is at the close of winter ; as, at this season, the change by which the mucilage of 

 the fruit is converted into oil has been completely effected ; and by longer delay the kernel grows 

 rancid, and the oil becomes of a vitiated quality. The nut is cracked by striking it on the end with 

 a small mallet ; and pains are taken not to bruise the kernel. The slight ligneous partition is 

 detached, and such kernels as are partially spoiled are picked out and thrown aside. The sound 

 kernels, thus cleared from every particle of the shell, should be sent immediately to the mill, as 

 they soon become rancid by exposure to the air. They are crushed by a vertical stone, which turns 

 in a circular trough, and is moved by a horse, or by water. The paste is next enclosed in bags of 

 strong linen, and submitted to the press. The oil which flows from this first pressure, without the 

 application of heat, is of the best quality. It is very clear, and is proper for food; but it sensibly 

 retains the taste of the nut, which, in general, is not agreeable to persons unaccustomed to it; so 

 that the consumption is limited to the departments where it is made. To be kept sweet for the 

 table, it should be drawn off several times during the first months, carefully corked, and kept in the 

 cellar, as it is more easily affected than any other oil by the action of air and heat. After the 

 fir»t expression, the paste is emptied from the sacks, moistened with warm water, and moderately 

 heated in coppers. It is then replaced in the sacks, and returned to the press. The oil of the 

 second discharge is highly coloured, and very speedily becomes rancid ; it is therefore employed 

 only in the preparation of colours. The cakes which remain after the expression is finished are 

 used, as already stated, for fattening swine, sheep, or fowls, or making candles. The principal use of 

 this oil is in the preparation of fine colours : it is preferred for this purpose, on account of the complete 

 and rapid manner in which it dries, and of the facility with which it is obtained in a perfectly limpid 

 state, which is done by diffusing it upon water in large shallow vases. 



In copperplate printing, walnut oil is considered, in Paris, indispensably necessary for a fine 

 impression, whether in black or in colours. But there are peculiar modes of preparing it for the 

 several colours with which it is to be mixed. Thus, for white, blue, light, and the intermediate 

 shades, it is reduced by boiling to two thirds of its bulk : but for dark green and black, to one fifth, 

 which leaves it a thick semifluid substance. To facilitate the process, one tenth part of linseed oil 

 is added to it : it is then placed in an iron or copper vessel over a strong clear fire. When it begins 

 to boil rapidly, the vessel is removed, and the oil takes fire by contact with the flame, and burns till 

 it is reduced to the proper consistency. Sometimes it is not allowed to kindle, but, when the ebullition 

 commences, crusts of bread are thrown into it, which remain till the necessary evaporation is effected, 

 and are then taken out, charged with mucilaginous particles. The principal advantage of this oil, 

 in the preparation of white lead for painting the interior of houses, as well as of the colours 

 employed in copperplate printing, is the longer and more perfect preservation of the tints. The 

 back of prints done with it, also, does not turn yellow like others. {Mich.r. N. Amcr. Sy/va,'M7, 148.) 



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