JAIC 2003, Volume 42, Number 3, Article 5 (pp. 425 to 439)
JAIC online
Journal of the American Institute for Conservation
JAIC 2003, Volume 42, Number 3, Article 5 (pp. 425 to 439)




This group of early photographic artifacts is extraordinary: strong, clear compositions produced with confidence using beautiful materials. The small-format negatives date from 1849 to 1850, and the large-format negatives are dated from 1850 to 1853 as well as being inscribed with a number. Overall the Flach�ron negatives are in very good condition, despite inherent fragility. Throughout the group, the image silver is neutral colored and appears stable. Flach�ron consistently employed the highest-quality Whatman paper for his negatives, and despite wear and tear from handling, the sheets have survived intact and in fact retain some of their original flexibility. Craquelure was observed in the gouache retouch media, although active flaking was not noted. Because the negatives were saturated with wax, handling dents and creases were visible throughout, although it should be noted that dents and creases are a common occurrence with this combination of materials. The organic components, paper and waxes, showed a minor degree of fungal growth. Considering the age of this material, these findings fall within the expected degree of deterioration. The growth does not appear to be active, and with proper storage and handling it should remain stable. The most striking condition characteristic, however, was the tonality of the applied wax layer that varied strikingly from light yellow to orange. In addition, four negatives appeared to have a natural resin coating, clearly visible under normal and specular illumination (figs. 8, 9 [see page 447]).

Fig. 8. Fr�d�ric A. Flach�ron, Comte, Arch of Titus, ca. 1850, paper negative, 24.2 � 33.0 cm, Department of Printing and Graphic Arts, Houghton Library, Harvard College Library. Horblit TypPr 815.F396.063 (N) Sz2. Normal light. Note the handling dents at center and opaque retouch in top right corner of sky.

Fig. 9. Fr�d�ric A. Flach�ron, Arch of Titus, 1850 (fig. 8). Specular light, showing brush application of coating

Visual inspection of the four negatives showed that the resinous coating was selectively applied to the negative: brush strokes outline the building forms but do not cover the surface completely. The thickness varies considerably from area to area, and a distinct cracking pattern from handling dents suggests the layer is brittle.

All of the Flach�ron negatives were examined under long-wave ultraviolet light. A visible fluorescence from ultraviolet excitation at certain wave-lengths is characteristic of specific substances, and long-wave ultraviolet radiation is frequently used, for example, in paintings conservation, to help distinguish overpaint from original paint or to ascertain the presence of natural resin varnishes or shellac. Four of the negatives examined under ultraviolet light showed a very strong, telltale, greenish auto-fluorescence typically associated with natural resin varnish. These were the same four negatives with coatings visible under normal illumination (fig. 10, see page 447). No other negative examined showed fluorescence (fig. 11, see page 448).

Fig. 10. Fr�d�ric A. Flach�ron, Arch of Titus, 1850 (figs. 8, 9). Ultraviolet illumination

Fig. 11. Fr�d�ric A. Flach�ron, Comte, End of Arch of Titus, Arch of Constantine Beyond, ca. 1850, paper negative, 27.4 � 35.3, Department of Printing and Graphic Arts, Houghton Library, Harvard College Library. Horblit TypPr 815.F396.065 (N) Sz2. Ultraviolet illumination. Note the absence of fluorescence.

While many of the photographic journals and manuals from this period of photography suggest that beeswax was the preferred transparentizing agent, other materials were available to and utilized by the photographers, such as oil, other waxes such as paraffin wax, gums, and resins (Blanch�re 1865). Beeswax has long been known for its chemical stability, due to its fully saturated long chain polymer components and the stability of the ester linkage. However, the addition of resins and gums, a practice historically associated with wax working, is of significance to the natural aging of these artifacts (Mills and White 1977).

Copyright � 2003 American Institution for Conservation of Historic & Artistic Works