Since the early nineteenth century, a membrane or wall has been central to the cell’s identity as the elementary unit of life. Yet the literally and metaphorically marginal status of the cell membrane made it the site of clashes over the definition of life and the proper way to study it. In this article I show how the modern cell membrane was conceived of by analogy to the first “artificial cell,” invented in 1864 by the chemist Moritz Traube (1826–1894), and reimagined by the plant physiologist Wilhelm Pfeffer (1845–1920) as a precision osmometer. Pfeffer’s artificial cell osmometer became the conceptual and empirical basis for the law of dilute solutions in physical chemistry, but his use of an artificial analogue to theorize the existence of the plasma membrane as distinct from the cell wall prompted debate over whether biology ought to be more closely unified with the physical sciences, or whether it must remain independent as the science of life. By examining how the histories of plant physiology and physical chemistry intertwined through the artificial cell, I argue that modern biology relocated vitality from protoplasmic living matter to non-living chemical substances—or, in broader cultural terms, that the disenchantment of life was accompanied by the (re)enchantment of ordinary matter.

This paper examines the history of biophysics at the University of Chicago, with a specific focus on the history of the Institute for Radiobiology and Biophysics (IRB), established at the university in 1945 as a continuation of the Manhattan Project. Discussed herein is how biophysical research developed at Chicago, and how the IRB formed the locus for early work in photosynthesis, phage genetics, and nucleic acid chemistry. The discontinuation of this institution in 1954 did not, however, terminate such work, but led to its dispersal into other entities within the university. Therefore the dramatic institutionalization of “molecular biology” and the creation of the Department of Biophysics under the presidency of George Beadle that commenced in the early 1960s relied upon a preexisting tradition rather than creating a new molecular phase in Chicago biology. This paper also shows that the interest in topics such as phage genetics and nucleic acid chemistry were continuous developments at Chicago from the early 1950s and did not represent a late interest in these topics.

This paper examines the contested "biological" meaning of the genetic effects of radiation amid nuclear fear during the 1950s and 1960s. In particular, I explore how the question of irreversibility, a question that eventually led to the discovery of DNA repair, took shape in the context of postwar concerns of atomic energy. Yale biophysicists who opposed nuclear weapons testing later ironically played a central role in the discovery of DNA excision repair, or "error-correcting codes" that suggested the reversibility of the genetic effects of radiation. At Yale and elsewhere, continuing anticipation of medical applications from radiation therapy contributed to the discovery of DNA repair. The story of the discovery of DNA repair illustrates how the gene was studied in the atomic age and illuminates its legacy for the postwar life sciences. I argue that it was through the investigation of the irreversibility of the biological effects of radiation that biologists departed from an inert view of genetic stability and began to appreciate the dynamic stability of the gene. Moreover, the reformulation of DNA repair around notions of information and error-correction helped radiobiologists to expand the relevance of DNA repair research beyond radiobiology, even after the public concerns on nuclear fallout faded in the mid-1960s.