‘Have you a table?’: epistemic instability, experimental tabulation, and the presentation of medical statistics in and after the Indian Plague Commission, 1898–9

The visualisation of data in tables has been essential to the historical development of epidemiological reasoning. As visual devices, tables have enabled epidemiologists to compare populations and establish multi-factorial association as a hallmark of modern epidemiology. While tables have usually been understood as instruments of ordering, this article argues that, in fin-di-siècle science, tabulation was a site of scientific experimentation and conflict, and that epidemiological standards later crystallised at least in part in response to the use and misuse of tabulation during these years. Drawing from an analysis of the tabulation practices found in the Indian Plague Commission (IPC) of 1898-99 - a landmark study which has not been fully integrated into the history of epidemiology - this article details how tables were introduced as powerful albeit inconsistent tools of epidemiological reasoning. We initially consider the testimony of medical officers in India, who used tables as an experimental tool to test the value of Haffkine's vaccine against plague. For commissioners, by contrast, tables were disruptive, equipped with the power of epistemic transgression. Contrary to the traditional function of tables as instruments of colonial order - useful for facilitating the abstraction and categorisation of colonised populations - tables in the IPC emphasised uncertainty and chance at the heart of epidemiological inquiry. This epistemic instability mattered, as we show, for the scientific community in Britain, where criticism of the IPC report stimulated sweeping debate on the presentation of contingency in medical statistics, advancing the formalisation of British epidemiology over the first decades of the twentieth century.