Synthetical Experiments and Alkaloid Analogues: Liebig, Hofmann, and the Origins of Organic Synthesis

This essay provides the first historical account of the origins of synthetic organic chemistry, one of the most powerful and productive of late nineteenth-century sciences. It builds on a revised understanding of the program of organic analysis instituted in the early 1830s by Justus Liebig, showing why and how Liebig guided his students August Wilhelm Hofmann and James Sheridan Muspratt in the introduction of synthesis to organic chemistry in early 1840s Giessen. What Muspratt and Hofmann called “synthetical experiments” became Hofmann’s main investigative method, but they did not enable the artificial laboratory production of specified target substances. Instead, synthetical experiments increased chemical understanding of reactions and their products. When applied to aniline, Hofmann’s model for natural alkaloids, they produced the array of artificial organic bases underpinning Hofmann’s major theoretical innovation, the ammonia type. Despite his reliance on artificial bases, this essay shows that Hofmann’s primary and enduring scientific goal was to understand the natural alkaloids. By revealing the essential stabilizing and progressive role of chemists’ daily work at a time when theory was uncertain and contested, it contributes to ongoing studies of science as practice.