This paper reveals that Josiah Willard Gibbs (1839-1903) attempted to explain certain chemical properties of matter, such as osmotic pressure of "diaphragms" (semi-permeable membranes) and electromotive force of chemical cells, from his theory of statistical mechanics, i.e., Elementary Principles in Statistical Mechanics (1902; EPSM). To begin with, I examine his thermodynamical theory developed in "On the Equilibrium of Heterogeneous Substances" (1876/78; EHS). Later, I attempt to support the above claim by analyzing his theory of statistical mechanics. In EHS and his later discussions on thermodynamics, Gibbs used thermodynamics to derive various properties of matter in equilibrium. Among others, "the fundamental equations" of thermodynamics and different "conditions of equilibrium," for both of which temperature, pressure and chemical potentials were essential, played a pivotal role in explaining these properties. With these two means, Gibbs explained a wide range of physicochemical phenomena such as diaphragms and chemical cells. In EPSM, Gibbs argued that some properties of ensembles corresponding to those of thermodynamical systems can be derived. I focus, in particular, on the properties of grand canonical ensembles, because he used them to deduce a formula analogical to one of the fundamental equations of thermodynamics, and to construct an analog of a diaphragm with corresponding conditions of equilibrium. Further, he included problems of chemical cells in the scope of statistical mechanics. Therefore, Gibbs' theory of statistical mechanics can be considered as a theory that attempted to explain the physicochemical domain.
Umeko Tsuda (1864-1929), a pioneering educator for Japanese women and the founder of Tsuda College, was a scientist. As an English teacher at the Peeresses School in Tokyo, the young Tsuda was granted a leave of absence by the government to study "teaching method" at Bryn Mawr College, a women's college near Philadelphia. During her stay in Bryn Mawr (1889-1892), however, she majored not in pedagogy but in biology, despite the fact that the Peeresses School officially banned science education for noble women. Following the vision of the feminist Dean Carrey Thomas, Bryn Mawr College offered full-fledged professional education in science comparable to that of Johns Hopkins University. Bryn Mawr's Biology Department was growing; there, Tsuda took courses from such notable biologists as Edmund B. Wilson, Jacques Loeb, and the future Nobel Laureate Thomas H. Morgan. In her third year, under Morgan, she carried out experimental research on the development of the frog's egg, which was published in a British scientific journal as their joint paper two years later. Tsuda was considered one of the best students in the department, and Bryn Mawr offered her opportunities for further study. However, after much consideration, she chose to return to Japan. Although Tsuda gave up a possibly great career as a biologist in American academe, she knew that it was almost impossible for a woman to pursue a scientific career in Meiji Japan and wanted to develop her dream of establishing an English school for women. Her experience of "forbidden" scientific study at Bryn Mawr seems to have given her great confidence in realizing her feminist ideal of enlightening Japanese women at the women's school she founded in 1900, the forerunner of Tsuda College.