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

NOTES TO CHAPTER I 217
Make an amalgam , without heat, of 16 g of leaf with 8 g of
. Dissolve the in 100 ml, or a sufficient quantity of pure
nitric acid of moderate strength; dilute this solution in about a
pound and a half of distilled water; agitate the mixture, and
preserve it for use in a glass bottle with a ground stopper.
“When this preparation is to be used, the quanitity of one ounce
is put into a phial, and the size of a pea of of or , as soft as
butter, is to be added; after which the vessel must be left at rest.
Soon afterwards small filaments appear to issue out of the ball of
which quickly increase, and shoot out branches in the form
of shrubs.
“For elective affinity I have my students read Query 31 of
Newton’s Optics.”
To view the silver tree, it is best to have binocular dissecting
microscopes with strong illumination. The dentritic forms and
“leaves” then show up to great effect. It should be possible to
watch the “tree of Diana” growing under the microscope, though I
have not been able to do so. A fume hood should be used if the
reaction is still proceeding.
When the solution of nitric acid is too strong, the reaction will
proceed too quickly for the formation of trees. A strong solution
and a copper leaf, for example, will produce immediate profusion
of bubbles and a fuzzy coating. Such a demonstration makes an
instructive contrast to the “organic” growth of the silver tree.
For those with a home chemistry set, similar results can be
obtained by mixing sodium silicate and water, and then adding
small quantities of aluminum sulfate, ammonium sulfate, cobalt
chloride, ferric ammonium sulfate, ferrous ammonium sulfate, or
nickel ammonium sulfate. Each of them makes a differently
colored tree. There are also gold trees; see French, The Art of
Distillation, op. cit., book 6.
18. For more terms see Jon Eklund, The Incompleat Chymist, Being an
Essay on the Eighteenth-Century Chemist in his Laboratory, With a
Dictionary of Obsolete Chemical Terms of the Period, Smithsonian
Studies in History and Technology, no. 33 (Washington, DC:
Smithsonian Institution, 1975).
19. Basil Valentine, Fratris Basilii Valentini Benedicter Ordens Geheime
Bücher oder letztes Testament. Vom grossen Stein der Uralten Weisen
und anderen verborgenen Geheimnussen der Natur (Strassburg:
Caspar Deitzel, 1645). This appeared in English as The Last Will and
Testament of Basil Valentine, translated by John Webster (London:
S.G. and B.G. for Edward Brewster, 1670), reprinted in 2 vols.
(Hildesheim: Dr. H.A. Gerstenberg, 1976), see vol. 1, 321–23.