Pratt, Nathaniel Alpheus

January 25, 1834–October 31, 1906

At the outbreak of the Civil War, Pratt organized the “Jordan Grays” and was mustered into service of the state of Georgia in November 1861.

Chemist, engineer, inventor. Pratt was born in Darien, Georgia, on January 25, 1834, the third of ten children of the Reverend Nathaniel Alpheus Pratt and Catherine Barrington King. He attended school at Roswell, Georgia; graduated from Oglethorpe University with an A.M. degree in 1852; and earned his M.D. from Savannah Medical College in 1856. On November 14, 1855, Pratt married Julia Eliza Stubbs at Milledgeville, Georgia. The couple had seven children. Pratt did not practice medicine but followed up with scientific studies at Harvard University. From 1858 to 1861 he was professor of chemistry at Savannah Medical College, followed by a brief tenure as a professor of chemistry and geology at Oglethorpe University.

At the outbreak of the Civil War, Pratt organized the “Jordan Grays” and was mustered into service of the state of Georgia in November 1861. Within a few months Pratt’s scientific abilities were recognized, and he was named assistant chief of the Confederate States Nitre and Mining Bureau at Augusta, Georgia. He was responsible for securing domestic supplies of raw materials for munitions (nitre being an essential component of gunpowder manufacturing). At the end of the war, Pratt was acting chief of the Nitrate Bureau, although he had earlier been bureau chemist and superintendent in charge of nitre service for the Second Division (Georgia, Alabama, and South Carolina).

Pratt moved to Charleston at the end of the war with plans to construct a chemical plant to manufacture fertilizers. In his earlier search for materials to manufacture gunpowder, Pratt realized that the rocky nodules he had discovered around Charleston Neck were phosphate of lime. After completing an analysis of this rock from the Ashley River basin and determining that it was the highest grade and most extensive, he organized the Charleston Mining and Manufacturing Company in October 1867, backed by George T. Lewis of Philadelphia. In 1868 Pratt organized the Sulphuric Acid and Super-Phosphate Company (also known as the Etiwan Phosphate Company), with C. C. Memminger as president. That same year Pratt published a pamphlet, Ashley River Phosphates History of the Marls of South Carolina and of the Discovery and Development of Native Bone Phosphates of the Charleston Basin.

His reputation as a scientist having been established, in 1870 Pratt left Charleston to become professor of applied science at Washington and Lee University in Virginia, a position he held until 1876. In 1872 Pratt received three patents for improvements in treating phosphate of lime, phosphatic rocks, and the manufacture of fertilizers with lime.

Pratt went on to discover halloysites and bauxite in Georgia and Alabama and the lithia waters near Austell, Georgia. He was also active in the organization of several fertilizer and mining companies. He served as Georgia’s state chemist (1879–1880) and geologist for the Georgia Department of Agriculture (1885–1889) and then went on to locate and develop phosphate deposits in Florida. On October 31, 1906, Pratt was killed in a train accident at Decatur, Georgia.

Donnelly, Ralph W. “Scientists of the Confederate Nitre and Mining Bureau.” Civil War History 2 (December 1956): 69–92.

Northen, William Jonathan. Men of Mark in Georgia. 6 vols. Atlanta: A. B. Caldwell, 1907–1912.

Citation Information

The following information is provided for citations.

  • Title Pratt, Nathaniel Alpheus
  • Coverage January 25, 1834–October 31, 1906
  • Author
  • Keywords Chemist, engineer, inventor, “Jordan Grays”, named assistant chief of the Confederate States Nitre and Mining Bureau at Augusta, Georgia,
  • Website Name South Carolina Encyclopedia
  • Publisher University of South Carolina, Institute for Southern Studies
  • URL
  • Access Date August 9, 2020
  • Original Published Date
  • Date of Last Update October 24, 2016
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