Scientific American Supplement, No. 443, June 28, 1884 | Page 5

painting
where his needs lie by first oiling the wood with raw oil, then
smoothing the surface down with lump pumicestone, washing it with a
mixture of japan drier or, better yet, gold sizing and turpentine, wiping
dry, and following it up with a coat of white lead, oil, and turpentine.
The explanation is: the raw oil penetrates the wood and raises the wood
fibers on the surface to be rubbed down with pumicestone, insuring the
best surface for the following painting: to harden the oil in the wood it
receives a coat of japan drier, which follows into the pores and there
forms a tough, resinous matter, resisting any air pressure that might
arise from within, and at the same time reacts on the first coat of lead as
a drier. This mode insures the smoothest and toughest foundation for
the following painting, and may be exposed to the hottest July sun
without fear of either blistering or peeling.
LOUIS MATERN.
Bloomington, Ill.
* * * * *

OLIVE OIL.

The following particulars with regard to the production of olive oil in
Tuscany have been furnished to Mr. Consul Inglis by one of the
principal exporters in Leghorn:
The olive oil produced in Tuscany from the first pressing of the fruit is
intended for consumption as an article of food. Hence, great attention is
paid both to the culture of the olive tree and the process of making oil.
The olive crop is subject to many vicissitudes, and is an uncertain one.
It may be taken as a rule that a good crop does not occur more
frequently than once in three years. A prolonged drought in summer
may cause the greater part of the small fruit to fall off the trees. A
warm and wet autumn will subject the fruit to the ravages of a maggot
or worm, which eats its way into it. Fruit thus injured falls to the
ground prematurely, and the oil made from it is of very bad quality,
being nauseous in taste and somewhat thick and viscous. Frost
following immediately on a fall of snow or sleet, when the trees are still
wet, will irretrievably damage the fruit, causing it to shrivel up and
greatly diminishing the yield of oil, while the oil itself has a dark color,
and loses its delicate flavor.
The olive tree in Tuscany generally blossoms in April. By November
the fruit has attained its full size, though not full maturity, and the olive
harvest generally commences then. The fruit, generally speaking, is
gathered as it falls to the ground, either from ripeness or in windy
weather. In some districts, however, and when the crop is short, the
practice is to strip the fruit from the trees early in the season. When
there is a full crop the harvest lasts many months, and may not be
finished till the end of May, as the fruit does not all ripen
simultaneously.
Oil made early in the season has a deeper color, and is distinguished by
a fruity flavor, with a certain degree of pungency; while as the season
advances it becomes lighter in color, thinner in body, and milder and
sweeter in taste. Oil made toward the close of the harvest in April or
May from extremely ripe fruit is of a very pale straw color, mild and
sweet to the taste, though sometimes, if the fruit has remained too long
on the trees, it may be slightly rancid. Oil very light in color is much

prized in certain countries, notably France, and hence, if it also
possesses good quality, commands a higher price in the Tuscan
markets.
The fruit of the olive tree varies just as much in quality as does the
grape, according to the species of the tree itself, the nature of the soil,
exposure, and climate of the locality where it grows. Some varieties of
the olive tree largely grown, because thought to be better suited to the
special conditions of some districts, yield a fruit which imparts a bitter
taste to the oil made from it; such oil, even when otherwise perfect,
ranks as a second rate quality.
The highest quality of oil can only be obtained when the fruit is
perfectly and uniformly sound, well ripened, gathered as soon as it has
dropped from the trees, and crushed immediately with great attention.
Should the fruit remain any time on the ground, particularly during wet
weather, it deteriorates fast and gets an earthy taste; while if allowed to
remain an undue length of time in the garners it heats, begins to
decompose, and will yield only bad oil.
The process of making oil is as follows: The fruit is crushed in a stone
mill, generally moved by water power; the pulp is then put into bags