J. Stewart Machin

1893 to 1973
Silicate Chemistry

J. Stewart MachinJames Stewart Machin was born in St. Louis, Missouri. He served in the U.S. Navy from 1917 to 1919 during World War I. He was an instructor in chemistry at Westminster College (Missouri) from 1922 to 1924 and a professor of chemistry at Sioux Falls College (South Dakota) from 1924 to 1936. He received his Ph.D. in physical chemistry in 1932 from the University of Chicago. He joined the Illinois State Geological Survey in 1936 as a chemist.

With time, Machin became a distinguished silicate chemist. He specialized in the properties of ceramic materials, enamelware, and bricks for the ceramics industry. He tested various mixtures of calcium, magnesium, aluminum, and silica oxides for their ceramic properties. In 1941, he became Head of the Industrial Minerals Division of the Geochemical Section. Machin used the wet chemical methods of his day for elemental analysis. In the late 1950s, however, he began to experiment with new spectrochemical methods to detect chemical elements. He applied the new method to determining vanadium in coal fly ash and copper, nickel, and vanadium in crude oils. In 1960, Machin was named Principal Chemist.

Machin authored or coauthored about 25 publications on the chemistry of mineral resources. Machin was a member of the American Association for the Advancement of Science and the American Chemical Society. He retired in 1962 after 26 years of service and then taught chemistry at Fresno State College in California. He is remembered by Roy Helfinstine, former Head of the Minerals Engineering Section as "being very precise in his work."

Honored by: 
Colonial Brick Corp. (Daniel A. Swartz) and Jonathan H. Goodwin
Citation Contributed by: 
William R. Roy