lead takes up the most oil; next, white lead, the pure carbonate Dutch
process made, following with zinc white and iron carbonates, as iron
ore paint, Turkey umber, yellow ocher; also faintly the chromates of
lead--chrome-green and chrome-yellow, finishing with the poorest of
all, modern white lead, made by the wet or vinegar process. The second
class being neutrals have no chemical affinity to linseed oil; they
need a large quantity of drier to harden the paint, and include all
blacks, vermilion, Prussian, Paris, and Chinese blue, also terra di
Sienna, Vandyke brown, Paris green, verdigris, ultramarine, genuine
carmine, and madderlake. The last seven are, on account of their
transparency, better adapted for varnish mixtures--glazing. The third
class of pigments act destructively to linseed oil; they having an
acid base (mostly tin salt, hydrochloride of tin, and redwood dye),
form with the gelatinous matter of the oil a jelly that will neither
work well under the brush nor harden sufficiently, and can be used in
varnish for glazing only; they are not permanent in color, and among
the most troublesome are the lower grades of so-called carmines,
madderlakes, rose pinks, etc., which contain more or less acidous
dyes, forming a soft paint with linseed oil that once dry on a job can
be twisted or peeled off like the skin of a ripe peach. All these
combinations of paint have to be closely observed by the painter to
insure his success.

Twenty-five years ago a house needed to be painted outside but once in
from five to seven years; it looked well all the time, as no dust
settled in the paint to make it unsightly. Painters then used the
Dutch-process-made white-lead, a base and raw linseed oil, a fat acid,
which formed the insoluble soap. They also put turpentine in the
following coats, to keep up the proportions of oil and pigment. All
held out well against wind and weather. Now they use the