He helped start MITs chemical engineering curriculum in the late 1880s. In 1887, he was appointed by the newly formed Massachusetts Board of Health to a landmark study of sanitary quality of the states inland waters. As consulting chemist to the Massachusetts State Board of Health, he was in charge of the famous Lawrence Experiment Station laboratory conducting the water sampling, testing, and analysis. There he put to work the environmental chemist and first female graduate of MIT, Ellen Swallow Richards. This research created the famous "normal chlorine" map of Massachusetts that was the first of its kind and was the template for others. As a result, Massachusetts established the first water-quality standards in America, and the first modern sewage treatment plant was created.
As a professor, Drown published a number of papers on metallurgy, mostly in Transactions of the American Institute of Mining Engineers. He was a founding member of the Institute, and served as its secretary, and editor of its Transactions from 1871 till 1884. He was elected its president in 1897.