COMMON EUROPEAN WALNUT. 
63 
in bags of strong linen and submitted to the press. The oil which flows 
under this first pressure without the application of heat, is of the best qua- 
lity. 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 stored 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 colored, and very speedily becomes rancid ; it is therefore em- 
ployed only in the preparation of colors. The cakes which remain after 
the expression is finished, are used for fattening fowls. 
Although nut oil, as an article of diet, is in general use in the Depart- 
ments where the tree abounds, it serves a still more important purpose in 
the preparation of fine colors. It is preferred on account of the complete 
and rapid manner in which it dries, and of the facility of obtaining it per- 
fectly limpid ; which is done by diffusing it upon water in large shallow 
vases. 
In copper-plate printing, walnut oil is considered, in Paris, indispensably 
necessary for a fine impression, in black or in colors. But there are peculiar 
modes of preparing it for the several colors with which it is to be mixed. 
Thus for white, blue, light green, 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 an active, clear fire. When it begins to boil 
rapidly, the vessel is uncovered, 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 colors employed in copper-plate printing, 
is the longer and more perfect preservation of the tints. The back of prints 
done with it do not turn yellow like others. 
A fine stomachic liquor is made with the fruit of the Walnut, gathered a 
month before its maturity. Twelve green nuts in the husk are bruised 
and thrown into a pint of good brandy; after they have steeped three 
wmeks, the brandy is filtered through brown paper, and a quarter of a 
pound of loaf sugar is added. This cordial improves by age. 
Dyers obtain, by boiling the husks when they begin to dscay, and the 
