Stephen Moulton Babcock (1843-1931) was an American agricultural chemist. He perfected the Babcock test for determining the butterfat content of milk, a great stimulus to the growth of the dairy industry.

Stephen Babcock was born on Oct. 23, 1843, in Bridgewater, N.Y., of Puritan stock. After graduating from Tufts University in 1866, he attended Cornell, where he was also a chemistry instructor; he obtained his doctorate in Germany at Göttingen in 1879.

Babcock invented an early method of simple milk analysis while working at the Geneva, N.Y., agricultural experimental station in 1881. He was professor of agricultural chemistry at the University of Wisconsin from 1887 to 1913 (emeritus thereafter), where most of his discoveries were made. He helped direct the Wisconsin state experimental station from 1901 to 1913.

Babcock's central interest was the chemical analysis of milk; but in 1890 he succumbed to pressure from the dairy industry and his Wisconsin colleagues to take...