“The Uncertain Method of Drops”: How a Non-Uniform Unit Survived the Century of Standardization

Abstract

Abstract This paper follows the journey of two small fluid units throughout the nineteenth century in Anglo-American medicine and pharmacy, explaining how the non-uniform “drop” survived while the standardized minim became obsolete. I emphasize two roles these units needed to fulfill: that of a physical measuring device, and that of a rhetorical communication device. First, I discuss the challenges unique to measuring small amounts of fluid, outlining how the modern medicine dropper developed out of an effort to resolve problems with the “minimometer,” which measured minims. Second, I explain how drops, utilized in “the open drop method” of administering general anesthesia, effectively communicated a gradual process and epistemically valuable heuristic to the audience of practitioners, whose attention to individual medical outcomes was important for verifying the proper dosage. The standardized minim was never able to achieve success as the drop’s intended replacement; the non-uniform drop better served the relevant epistemic goals within the practical contexts for which these units were designed. The surprising historical trajectory of drops should cause us to question the common equivocation of “standardization” with “progress” in the history and philosophy of measurement. This study also exemplifies how examining non-standard measurement practices can be instructive for better understanding the role and function of standardization within epistemology of measurement.