859
Extracts of many plant dyes are fugitive colours and
fade within hours or days of exposure to sunlight. They
provided Sir John Herschel with his unfi xable Anthotype
process. A more permanent, positive-working organic
photochemical process results from the decomposition
of diazonium salts by light:
UV light + C 6 H 5 N 2 + Cl– + H 2 O → C 6 H 5 OH + N 2 +
HCl
phenyl diazonium chloride + water → phenol + nitrogen
- hydrogen chloride
The diazonium salt that remains can couple with phe-
nolic molecules to produce azo-dyes in a variety of
colours, e.g.:
C 6 H 5 N 2 + + C 10 H 7 OH → C 6 H 5 N=N C 10 H 6 OH + H+
Phenyl + ß-naphthol → benzene-azo-ß-naphthol +
hydrogen ion
diazonium cation (a red dyestuff—Sudan I)
This reaction forms the basis of the Primuline and
Diazotype processes.
Mike Ware
See also: Salted Paper Print; Calotype and Talbotype;
Photogenic Drawing Negative; Platinum Print;
Positives: minor processes; and Cyanotype.
Further Reading
Bowen, Edmund John, The Chemical Aspects of Light, Oxford:
Oxford University Press, 1946.
Eder, Josef Maria, Ausfürliches Handbuch der Photographie
[Comprehensive Manual of Photography], Halle, Knapp,
1899; idem, History of Photography, trans. Edward Epstean,
New York: Colombia University Press, 1945.
Hardwich, Thomas Frederick, A Manual of Photographic Chem-
istry, London: John Churchill, 1855.
Hunt, Robert, A Popular Treatise on the Art of Photography,
Glasgow: Richard Griffi n, 1841; idem, Researches on Light,
London: Longman, Brown, Green, and Longmans, 1844;
idem, A Manual of Photography, 4th ed., London: Richard
Griffi n, 1854.
James, TH (ed.), The Theory of the Photographic Process, 4th
ed., New York: Macmillan, 1977.
Kosar, Jaromir, Light Sensitive Systems: Chemistry and Appli-
cation of Non Silver Halide Photographic Processes, New
York: Wiley, 1965
Marignier, Jean-Louis, “Asphalt as the World’s First Photopoly-
mer—Revisiting the Invention of Photography” in Processes
in Photoreactive Polymers, edited by V. V. Krongantz and A.
D. Trifunac, New York: Chapman and Hall, 1995.
Meldola, Raphael, The Chemistry of Photography, London:
Macmillan, 1889.
Neblette, C. B., Photography: its Principles and Practice, 4th
ed., London: Chapman and Hall, 1942.
Vogel, Hermann, The Chemistry of Light and Photography,
London: Kegan, Paul, and Trench, 1888.
Ware, Mike, “On Proto-photography and the Shroud of Turin” in
History of Photography, 21/4, Winter 1997, 26116–9.
LINDSAY, SIR COUTTS (1824–1913)
English painter and photographer
Sir Coutts Lindsay, painter and founder of the Grosvenor
Gallery, was born in 1824 on the outskirts of London, the
son of Colonel James Lindsay and Anne, both of whom
were interested in the arts. After a stint in the army,
Lindsay studied painting in the 1840s and early 1850s
and exhibited paintings at the Royal Academy in the
1860s. He married Caroline Blanche Fitzroy in 1864. He
took up photography at some point in the late 1840s or
1850s and made salted paper prints. His subjects mostly
consisted of landscapes and architecture, particularly
views of Italy. Examples of work attributed to Lindsay
are in the collection of the Getty Museum and the Harry
Ransom Humanities Center at the University of Texas,
Austin. He was also photographed by David Wilkie
Wynfi eld and Julia Margaret Cameron in the 1860s.
Lindsay is most well-known for founding the Grosvenor
Gallery in 1877, which for a number of years rivaled the
Royal Academy as the most important exhibition venue
for British artists. Lindsay died in 1913.
Diane WaggonerLINDT, JOHN WILLIAM (1845–1926)
One of Australia’s pre-eminent photographers, John
Lindt produced a large volume of high quality pho-
tography, remarkable for its thematic range, aesthetic
consistency and technical accomplishment. His pursuit
of landscape and ethnographic subjects, coupled with a
rare entrepreneurial fl are, continued throughout a half
century career. During his early Grafton years, from
1869–1876, Lindt produced a number of signifi cant
photographic portfolios, including Australian Aborigi-
nals (c.1873–1874); Australian Types (c.1873–1874);
and Characteristic Australian Scenery (1875). The
latter series, commissioned by the New South Wales
Government for the 1876 Philadelphia Centennial
Exhibition, contains images such as The Artist’s Camp
(Near Wintervale) (1875) (Grafton Regional Gallery),
and Tower Hill Creek, N.S.W. (1875) (National Library
of Australia) which demonstrate Lindt’s exceptional
compositional ability and meticulous attention to expo-
sure and printing technique, qualities apparent in much
of his later work.
Strikingly, these early portfolios indicate Lindt’s
emblematic cast of mind to work ambitiously within
defi ned pictorial categories. Like his contemporary
and friend, Nicholas Caire (1837–1918), Lindt pro-
duced photographs with one eye fi rmly focused on
the burgeoning national and international markets for
such productions. When Lindt’s Australian Aboriginals
was marketed in late 1874, it was considered “the fi rst