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

NOTES TO CHAPTER I 223
“Place 8 g. of iron…in a crucible. Cover, and heat with a
Fisher Burner until redhot. Then introduce, in
approximately 2 g. portions, 18 g. of antimony trisulphide.
Cover the crucible after each addition, and allow the
trisulphide to melt before each subsequent addition. After
all 18 g. are added and melted, use a long glass or iron rod
to stir the pasty mixture as well as possible (a considerable
lumpy mass of unreacted iron nails will remain at this
point).
“Then cautiously add 6 g. potassium nitrate in about 1 g.
portions. Operate carefully, on each addition of postassium nitrate,
there will be a strong deflagaration—lift off the crucible lid a little
with tongs, and cast in the portion of nitrate quickly all at once,
and close the lid immediately, When each deflagaration is finished,
add the next portion.
“After all the nitrate has been added, stir the mixture well, and
heat the crucible (covered) strongly for seven or eight minutes. Stir
once gently, and then pour out the contents into another crucible.
Much viscous material will remain in the melting crucible, but the
easily liquid molten antimony should pour out into the other
crucible fairly easily. If the crucible containing the scoriae is
soaked in water for a few hours, most of the unwanted material
dissolves or softens, and often a few additional buttons of
antimony metal can be retrieved.
“Purification and the ‘rising of the star’:
“Grind the metallic antimony coarsely, and add to it 2.5 g. of
potassium nitrate. Mix well, and place the mixture into a crucible,
cover, and heat. When the material is molten, pour it out into
another crucible, allow the metal to cool, separate the golden slag
by either chipping or washing it away, and take the metal. Repeat
this operation using another 2.5 g. of potassium nitrate. Repeat the
operation one last time, and when the mixture is completely
molten (it will look like quicksilver with oil floating on it) pour it
quickly into a hot crucible and cover it immediately.
“Let it cool slowly, and then use hot water to wash away the
whitish slag. The star, sometimes looking more like a fern, will be
clearly visible on the surface of the metal (wherever it was covered
by the slag while cooling). (Note: the larger the quantity of metal,
the better the star will appear.)
“Note: the fumes of volatile white antimony oxide which are
given off whenever the material is molten, are toxic. Work in good
ventilation, such as a fume hood.”