What Painting Is: How to Think about Oil Painting ... - Victoria Vesna

62 HOW TO COUNT IN OIL AND STONE
phlogiston, and revealing both the fire and the remaining
substance. Hence the phlogiston the-ory, which stands at the
threshold of chemistry, can be understood as a further reduction
of the number of elements in the log. At first it was four, in the
system used by the Greek and Arabic writers, then it was three,
in some treatises of Renaissance alchemy, and finally two, in the
eighteenth-century phlogiston theory.
It seems as if the quaternion, as it was called, is an especially
sturdy number. Jung proposed four colors as the standard
alchemical sequence: black, white, yellow, and red. In Greek
natural philosophy, the four elements—earth, air, fire, and water
—have four associated qualities—moist, dry, hot, and cold. (The
alchemists call them qualitates. 36 ) The four elements do not
correspond exactly to the four qualities, so the arrangement is
sometimes imagined as a square of elements with sides that are
qualities: Many things make sense with the help of this diagram.
Fire is hot and dry, water is cold and moist. When earth
(meaning anything in and on the earth) is heated, it becomes dry
and catches fire. When air becomes too moist, it rains as water.
The inscribed square shows that grease is cold, since it is a little
more like earth, and oil is moist, since it is nearer to air. To the