Values in the Development of Early Periodic Tables

Julius Lothar Meyer, John Newlands, and Dmitrii Mendeleev were amongst the discoverers of the periodic system of the elements. Although their systems are similar enough to be recognised as the precursors for the modern periodic system, they were also different. Here, I argue that many of their differences can be explained in terms of how the chemists emphasised different values in the process of developing their systems. In particular, Newland highlighted the simplicity of his arrangements; Meyer was more careful about the quality of data that gave rise to his system of elements; and Mendeleev sought to make his system more complete. By shedding light as to how the values of simplicity, completeness and carefulness guided the development of early periodic systems, this paper contributes to a broader understanding of how values influence science.