Making molecular identity


"Index workers" in 1938, plus a paper form used to computerize molecular identity




Creative Commons Licence



Contributed date

November 26, 2018 - 5:05pm

Critical Commentary

Substantive Caption:

The main image depicts the editorial offices of Chemical Abstracts, circa 1938. For most of the 20th century and through the present-day, the abstract journals, collective indexes, and databases of Chemical Abstracts (now Chemical Abstracts Service, or CAS) have been the authoritative source for bibliographic and regulatory information about chemical substances and the chemical sciences, including allied fields such as toxicology. In this image, “index workers” are engaged in compiling an annual or decennial index of the publication. The vast majority of these cards refer to individual chemical substances rather than subject headings or author names. Much index labor involved writing, rewriting, cross-referencing, and error-checking the systematic chemical names that were the key to the whole enterprise, since they allowed for the arrangement of hundreds of thousands (today hundreds of millions) of substances in chemically-meaningful alphabetical order. This work was particularly challenging because the research chemists who wrote the journal articles abstracted and indexed in Chemical Abstracts often did not themselves use systematic names. This was both because the names were cumbersome and because the uniform chemical ontology that they expressed was sometimes a poor fit for how chemists defined the substances that their research addressed.

 “Among personal characteristics for this type of work accuracy perhaps should rank highest, and with that conscientiousness, patience, a meticulous attentiveness to detail (without a loss of perspective of relative values, since a great deal of work has to be turned out, at times under considerable pressure), power of concentration, good judgment, and interest in words as words, a love of puzzles and of guessing and digging out elusive ideas, meanings, words, and formulas. An interest in things rather than people is likely to lead to greater satisfaction in this type of work, since the opportunities for personal professional contacts outside the office are relatively few. The analytical rather than the creative type is probably best suited to this kind of work. Good eyes (at least strong ones) are absolutely essential, while the ability to sit hour after hour without much relief is a requirement not to be laughed off. Work of this nature is not for the overly energetic or restless person” (Scott 1938, 275; italics in original).

The inset image depicts a form of the sort that was used when CAS re-created this whole operation on digital computers during the 1960s.

Design Statement:

  • Molecular identity is not given by nature – not entirely, anyway.
  • Rather, it is the product of human choice and human work, entrenched within systems of information technology and bureaucracy.
  • Recognizing this and tracing its history can help shed light on the default ways in which toxic subjects have come to be visualized and not-visualized.

Molecular identity is not given by nature. Rather, it was made in meeting rooms and editorial offices, for the purposes of organizing information about chemical substances, in order to support research and development within the turn of the century synthetic chemicals industry (Hepler-Smith 2015a; Hepler-Smith 2015b; Hepler-Smith 2016). And both making and maintaining this system of molecular identity took (and takes) a whole lot of *work*.

My intention in juxtaposing these images is to direct historical and ethnographic attention to the situated practices—including especially bureaucratic practices—through which the simplicities, complexities, and uncertainties of environmental toxicity are constituted. They are typically taken to be baked into the material nature of chemical substances and bodies. To a certain degree, they are; but they are also the product of a way of ordering the world of substances that I am calling “molecular bureaucracy” (Hepler-Smith 2019). The institutions, practices and technologies that render the world molecular (cf. Myers 2015) entail simplifications, frustrations, fortuitous affordances, and regrettable consequences. Training our vision on easily-overlooked legal definitions, information technologies, administrative procedures, clerical labor, and nomenclature conventions can help shed light on why toxic subjects get visualized in the ways they do.


Hepler-Smith, Evan. 2015. "'Just as the Structural Formula Does': Names, Diagrams, and the Structure of Organic Chemistry at the 1892 Geneva Nomenclature Congress." Ambix 62 (1): 1-28. doi: 10.1179/1745823414Y.0000000006.

Hepler-Smith, Evan. 2015b. “Systematic Flexibility and the History of the IUPAC Nomenclature of Organic Chemistry.” Chemistry International 37 (2): 10-14. doi: 10.1515/ci-2015-0232.

Hepler-Smith, Evan. 2016. “Changing Names and Naming Change: Transformations in the ‘International Machinery’ of Chemical Information.” Proceedings of the International Workshop on the History of Chemistry, March 2-4 2015, Tokyo. 68-76.

Hepler-Smith, Evan. 2019. "Molecular Bureaucracy: Toxicological Information and Environmental Protection." Environmental History 24 (3). Forthcoming.

Myers, Natasha. 2015. Rendering Life Molecular: Models, Modelers, and Excitable Matter. Durham: Duke University Press.

Scott, Janet D. 1938. “The Chemist at Work. XIV. My Work with Chemical Abstracts.” Journal of Chemical Education 15 (6): 271–75. doi: 10.1021/ed015p271.


Main image: reprinted with permission from Janet D. Scott, “The Chemist at Work. XIV. My Work with Chemical Abstracts,” Journal of Chemical Education 15, no. 6 (June 1, 1938): 271–75, Copyright 1938, American Chemical Society.

Inset image: Zatopleg form for ciphering chemical structures, 20 June 1956, Box 20, Folder 46, Calvin N. Mooers Papers, Charles Babbage Institute, University of Minnesota Archives, Minneapolis, Minnesota.




Columbus, Ohio and Cambridge, MA
United States