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

A SHORT COURSE IN FORGETTING CHEMISTRY 25
4. acid juices (succi acres), including copperas and “metallic ink”
(melanteria),
5. oily juices (succi pingues), including sulfur, bitumen, and pit
coal,
6. marine stones, including sponges, corals, and the Halcyon
Stone (alcynium), which was thought to be a “stony
concretion” of sea foam,
7. earths resembling stones, including manganese, calamine,
and the legendary Stone of Assos (sacrophagus), 26
8. stones engendered in animals, including bezoar, stag’s tears,
toad-stone, and pearls,
9. stones in the shapes of animals and plants (lapides
idiomorphoi), and
10. marbles. 27
I wonder if anyone these days could do as well, juggling what
could be actually seen with the legendary stories told by travelers
and ancient authors.
Gases were especially hard to figure out, since they are mostly
invisible. Jean-Baptiste Van-Helmont, who coined the word
“gas,” tried his hand at classifying them and ended up with six
species of the new substance:
1. gas produced by burning wood, which he called “woody
spirit” (spiritus sylvestris),
2. gas produced by fermenting grapes, apples, and honey,
3. produced by the action of acid on calcareous bodies,
4. produced by caverns, mines, and cellars,
5. produced by mineral waters, and
6. produced by the intestines. 28
This list is probably more elaborate than anything we might draw
up without calling on some memory of elements like nitrogen,
helium, and oxygen. Even a modern chemistry lab, where the
gases can be sampled in their pure states, would not be much
help. If we were to smell bromine—a choking red gas with a
suffocating odor—would we know how to tell it from iodine
vapor, or any number of disagreeable violet gases? And even if we
managed to construct Van-Helmont’s list, where would we go
from there? Would it help to classify gases by their smells? Are
“visible gases” such as steam different from invisible ones? Does