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This is major study of early British photography (daguerreotypes), patent law and authorship based on extensive archival research, examination of the current literature on intellectual property law, and theories of the self. It is the first output from my Leverhulme Trust funded research on intellectual property law, photography and biography. Included are ten previously unpublished early daguerreotypes. A work of cutting-edge cultural history which, through studying the case law of early photography legal depositions and affidavits, held at the National Record Office, Kew, this essay reflects on the way that authorship and careers were shaped and constrained. In addition to lectures in British universities, I have presented preliminary versions of this paper at Yale University and University of California, Berkeley and as key-note addresses at the University of Bergen and the University of Leeds. While there has been much recent discussion of copyright, patents remain under researched as cultural phenomena. However, I argue that patent law played a central role in defining modern conceptions of art and photography by joining intellectual property with image production, to create a distinctly modern sphere of authorship. My essay focuses on the prosecutions, conducted during the 1840s and 1850s, by the British patent holder for the daguerreotype - the merchant Richard Beard. Investigating Beard’s business model for his three London studios and subsidiary licensed studios, I ask what authorship meant in the case of a mass-image producing enterprise, which employed dozens of operators as well as numerous subsidiary photographers all trading under license to Beard. My essay brings a fresh historical perspective to debates on the nature of authorship, considering the special characteristics of collective making and the mass production of portraits.

The data in this paper show that when the inhibition of growth is measured, xeroderma pigmentosum (XP) complementation groups A, G and D are very sensitive to 4-nitroquinoline-1-oxide (4NQO), whereas only XP groups G and D are very sensitive to 3-methyl-4NQO (3me4NQO). Cells belonging to XP-C group are not particularly sensitive to either agent. Thus there are different epistasis groups for the excision repair of DNA adducts induced by these agents as opposed to the repair of u.v. damage. DNA polymerase alpha is involved in the repair of 4NQO-induced lesions because aphidicolin blocks their repair. XP cells from all the above groups are defective to some extent in this repair. The degree of repair defectiveness follows that seen after u.v., with even the XP-C cell line used having reduced repair (despite the fact that the inhibition of growth by 4NQO in this cell line was not markedly different from normal). Aphidicolin did not induce breaks in the normal or XP cell lines exposed to 3me4NQO, thus the repair of lesions induced by 3me4NQO does not involve DNA polymerase alpha in any of the cell lines. Finally, catalase reduces the alkaline labile lesions induced by 4NQO, but not 3me4NQO, suggesting the latter agent does not induce substantial amounts of DNA damage by the generation of radicals.

4-Nitroquinoline-1-oxide (4NQO) reacts with DNA primarily at the N2 and C8 of guanosine, with a small percent of reaction at the N6 of adenosine. In human cells it has been unclear whether or not all 4NQO-induced adducts are removed by a nucleotide excision repair mechanism. In this paper we demonstrate that the inhibitor of DNA polymerases alpha and delta, aphidicolin, blocks the repair of all 4NQO adducts. Hence excision repair must operate on all of these lesions. After 4NQO the residual excision repair seen in a xeroderma pigmentosum group A cell line virtually totally defective in UV repair was 40-60% of that in normal cells. Therefore there must be some differences between the excision repair operating on UV as opposed to 4NQO-induced DNA damage.

1-Nitropyrene, 1-nitrosopyrene and 1-aminopyrene were investigated for their ability to induce covalently bound DNA adducts in calf thymus DNA and Chinese hamster lung fibroblasts. Xanthine oxidase catalysed the induction of one major and one minor DNA adduct in 1-nitropyrene- or 1-nitrosopyrene-treated calf thymus DNA, whilst 1-aminopyrene was inactive. These compounds did not form detectable DNA adducts in the absence of xanthine oxidase. The major DNA adduct produced by 1-nitropyrene and 1-nitrosopyrene in calf thymus DNA co-migrated on h.p.l.c., and the structure was consistent with that previously described by others as N-(deoxyguanosin-8-yl)-1-aminopyrene. The compounds were investigated for their ability to form DNA adducts in Chinese hamster lung fibroblasts. 1-Nitropyrene (5.2 pmol/mg DNA/h) and 1-nitrosopyrene (129 pmol/mg DNA/h) formed a single DNA adduct in Chinese hamster lung cells which co-eluted on h.p.l.c. with the C-8 deoxyguanosine adduct isolated from 1-nitropyrene-treated calf thymus DNA. 1-Nitrosopyrene was the most efficient compound investigated for the production of the C-8 guanine adducts. In contrast, 1-aminopyrene (14.7 pmol/mg DNA/h) induced the formation of a DNA adduct which did not co-elute with the C-8 guanine adduct. The data presented here suggest that 1-nitropyrene and 1-aminopyrene are metabolized to reactive intermediates which form different DNA adducts in Chinese hamster lung fibroblasts.

The experiments reported here have investigated the induction of ethylations to DNA in yeast cells exposed to the chemical mutagen ethylnitrosourea. A similar level of alkylation was seen at the N7 and O6 of guanine and at the N3 of adenine in either log phase cells or in temperature-sensitive cdc4 and cdc7 cells growth arrested at their specific G1 positions. Hence the changes in chromosome structure associated with the above cdc phenotypes do not modify the amount of DNA damage induced by ethylnitrosourea.