ie 
CHAP. CII. JUGLANDA‘CEX. JU GLANS. 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 cakes, 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. a 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 off 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 black 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 devs 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 itis 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 pomertey, 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, with. in general, is not agreeable to persons unaccustomed to it; so 
that the consumption is limited to the departments where it ismade. 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 
first 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 1s therefore employed 
only in the preparation of colours. The cakes which remain after the expression is finished are 
, 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 accountof 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 jeaves it a thick semifluid substance. To facilitate the process, one tenth part of linseed oil 
1s added to it: it is then placed, in an iron or aie vessel over a strong clear fire. Whenit 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 Poh 33 The principal advantage of this oil, 
in the preparation of white lead for painting the interior of houses, as well as of the colours 
joyed inj copperplate printing, is the longer and more perfect preservation of the tints. The 
‘of prints done with it, also, does not turn yellow like others. (Michxr. N. Amer. Sylva,147, 148.) 
5a 4 / 
