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

Tin is made from pure quicksilver mixed with pure white
sulfur. But it is only cooked for a short time. If the heat is
too small and the time is too great, it will turn into silver.
Lead is made from coarse quicksilver mixed with coarse
sulfur that is white with just a little red. 31
Needless to say, by modern standards most of this is mistaken:
lead is not made from sulfur, but is an element in its own right,
and so are tin and iron. Marius also struggles with the precision
of language. What, a modern chemist might ask, is a “long time”?
What is a “moderate heat,” or a “small amount of redness”?
Without quantifiers, Marius’s distinctions are just rules of
thumb, incomplete descriptions that have to be corrected by
experience. That is the problem that confronts artists, because
they are interested in nuances of mixture. It is not possible to
make a recipe for the textures Monet used, or the colors he mixed;
instead, the student has to see them made, and then repeat the
process as accurately as possible.
Without the instruments of quantitative science the world will
remain a blur. Here, as a last example, is a concerted attempt to
order the world: a list summarizing an anonymous medieval
treatise traditionally ascribed to the Arabic alchemist Gābir Ibn
Hajjān. The book, called the Summa perfectionis, was widely
consulted until well after the Renaissance, and it does an excellent
job at bringing order to the study of “earthly things.” 32 When I
read through it, I marvel that so much clarity could be brought to
the world of confused and nameless objects:
I. Terrena (“Earthly things”)
A SHORT COURSE IN FORGETTING CHEMISTRY 27
A. Four Spirits [i.e., volatile substances]
1. Quicksilver
2. Sal ammoniac [ammonium chloride, NH4Cl]
a. Mineral form
b. Dirty, yellow form
c. Artificial form produced from hair
3. Auripigment [arsenic sulfide]