During the nineteenth century, physicists and chemists, using different linguistic modes of expression, sought to describe the world for different purposes; thus, both disciplines gradually were nudged toward demarcation and self-image identification. In the course of doing so the rich complexity of the empire of chemistry was born. The essential challenge was closely connected with analysis, synthesis, and chemical process: learning the art of watching substances change and making substances change. Pursued in theory-poor and phenomenology-rich contexts chemistry nevertheless made itself intellectually, professionally, societally, and industrially creditable and attractive. The developing links between physics and chemistry are examined in this paper from the perspective of the discipline of chemistry more specifically than from the side of physics. Chemists came to believe that essentially physics was no more than mechanics. All else belonged to the domain of chemistry.

Not before the last decades of the century were firm collaborative links and genuine reciprocity fostered between physics and chemistry, and then primarily on account of the common utility of scientific research tools. At a more fundamental level physics and chemistry, in contradistinction to all the other natural sciences, experienced partial overlap and convergence because of unique mutual reliance on the construction of systems each according to its own theoretical conceptions. Still amalgamation was unthinkable. Eventually physical chemistry was loosened from chemistry in the same way that, somewhat later, chemical physics was emancipated from physics. The intrinsic messiness of chemistry, one might suggest, tends more readily to foster Bohr's opinion that “there is no rock bottom to the study of nature,” rather than Einstein's view that “we can realistically, ultimately, put it all together.”