FW: Prussian Blue, or the Pencil of Nature | Pierre Laszlo]

[Miguel Lourenço]

> Chamo a vossa atenção para a seguinte palestra, que me parece ser muitíssimo
> interessante .
>
> Vai ser na Faculdade de Ciências (não no Museu de Ciência).
> A organização é do CIUHCT e a sala ainda vai ser anunciada (vão vendo na
> página do CIUHCT, http://chcul.fc.ul.pt/).
> 28 de Outubro, 17 h
>
> "Prussian blue, or the pencil of nature"
> Pierre Laszlo, Ecole polytechnique, Palaiseau, France
> and University of Liège, Belgium
>
> Abstract:
> Prussian blue, the synthetic pigment invented in the eighteenth century, has
> had many uses, including the blueprint and Caselli's pantelegraph (1861), an
> ancestor of the fax machine. This lavishly illustrated talk will focus on
> applications to the visual arts. The novel blue pigment, used in paints
> (e.g.
> Vincent van Gogh) and in inks, enjoyed much use for watercolors.
>
> In mid-nineteenth century, the French artist Constantin Guys, Baudelaire's
> friend, routinely sketched a scene or a character with Prussian blue ink,
> obtained from Parisian suppliers. It would be transferred to a lithographic
> engraving for a magazine such as L'Illustration: such articles illustrated
> by Guys's work using Prussian blue antedated the photographic reports
> familiar to us.
>
> The astronomer John Herschel (1792-1871) devised in 1842 the cyanotype, a
> photographic process using paper treated with photosensitive Prussian blue.
> Upon light exposure, and subsequent fixation with sodium thiosulfate,
> durable
> images result. One of its inventors, William Henry Fox Talbot (1800-1877),
> came up in 1844 with the metaphor of "The Pencil of Nature" for the
> ability of photography to capture natural scenes, in their realistic
> truth-or so he construed. A joint friend of Fox Talbot and of Herschel, Anna
> Atkins (1799-1871), took to cyanotypes with scientific rigor and with
> enthusiasm. The daughter of the chemist-zoologist John George Children
> (1777-1852), she was brought up in the presence of many of the leading
> English
> chemists at the time, including Humphry Davy. She devised numerous
> photograms,
> of a similar type as Man Ray for instance would make famous in the first
> half
> of the twentieth century. She embarked on a botanical project, of awesome
> magnitude, of thus recording the morphology of a wide variety (424 different
> specimens) of algae. "The difficulty of making accurate drawings of objects
> as
> minute as many of the Algae and Conifera, has induced me to avail myself of
> Sir John Herschel's beautiful process of Cyanotype, to obtain impressions of
> the plants themselves," she wrote in october 1843. The resulting book,
> British
> Algae: Cyanotype Impressions, was the very first to be photographically
> illustrated and printed, between 1843 and 1853.
>
> I shall present and comment upon her compositions, attempting to delineate
> the
> artistry from the science. Prussian blue thus highlights Socrates's
> definition of the beautiful as the useful.
>
> References
> Ludi, A., "Prussian Blue, an Inorganic Evergreen", Journal of Chemical
> Education 1981, 58, 1013.
> Barbara H. Berrie, "Prussian Blue." In Artists' Pigments: A Handbook of
> their History and Characteristics, vol; 3, National Gallery of Art,
> Washington
> DC, 1997, 191-217.
> Dunbar, K. R. and Heintz, R. A., "Chemistry of Transition Metal Cyanide
> Compounds: Modern Perspectives", Progress in Inorganic Chemistry, 1997, 45,
> 283-391.
> Prakash R. Somani and S. Radhakrishnan, "Electrochromic response in
> polypyrrole sensitized with Prussian Blue" Chemical Physics Letters, 1998
> 292,
> 218 - 222
> Peter Frederick, Creative Sunprinting, Focal Press, NewYork, 1980.
>
>
>
>
>

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