From botanics to physics: Henri Devaux (1862–1956) and the origins of surface science

This article explores the interdisciplinary career and overlooked legacy of Henri Devaux (1862-1956), a French botanist-turned-physicist whose pioneering work on thin films and surface science predated the field's maturity. Trained as a botanist, Devaux crossed disciplinary boundaries to make foundational contributions to the study of thin films anticipating key developments in molecular biology and colloid chemistry. Despite this, his work remains marginalized in narratives dominated by figures like Irving Langmuir and Agnes Pockels. Devaux's career reflects the tensions of disciplinary transgression in early 20th-century France, bridging botany, physics, and chemistry while serving as an "ambassador" of plant physiology within physics. His devout Protestant faith further shaped his scientific identity: he framed research as a divine mission and conceived of "Complete Science"-a synthesis of empirical inquiry and religious revelation-that distinguished him from both secular and Catholic contemporaries. Drawing on his personal archives, this study argues that Devaux's legacy was shaped by experimental ingenuity, religious conviction, and deliberate navigation between institutional constraints. His story challenges standard narratives of scientific progress, illuminating how personal belief and disciplinary boundary-crossing can simultaneously drive innovation and limit historical recognition.