In his laboratory at Western Reserve University (Now Case Western Reserve University), Edward W. Morley carried out his research on the atomic weight of oxygen that provided a new standard to the science of chemistry. The accuracy of his analyses has never been superseded by chemical means. His great work, published in 1895, also gave important insight into the atomic theory of matter.

He observed, after carefully analysis of the volume proportions in which hydrogen and oxygen unite, that the atomic weight of oxygen was 15.879.

The plaque commemorating the event reads:

In his laboratory in the basement of this building, Edward W. Morley, Hurlburt Professor of Natural History and Chemistry from 1868 to 1906, carried out his research on the atomic weight of oxygen that provided a new standard to the science of chemistry. The accuracy of his analyses has never been superseded by chemical means. His great work, published in 1895, also gave important insight into the atomic theory of matter.