Wallace Hume Carothers (1896-1937) was a chemist and inventor of Neoprene artificial rubber and Nylon synthetic fiber. He worked as a chemist in E.I. du Pont de Nemours & Company's Fundamental Research Program from 1928 until his death in 1937. From 1915 to 1920, he attended Tarkio College in Missouri as a science major. This collection of Carothers' letters was written to and preserved by a close friend, Wilko Gustav Machentanz (1895-1973), with whom Carothers roomed for two of his years at Tarkio. The bulk of the letters were written between 1917 and 1922, before Carothers became absorbed in his doctoral studies, although the two corresponded as late as 1936.