gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1994.58A.2.160 Biotic Enhancement of Weathering Redux Schwartzman D. Department of Biology, Howard University, Washington, D.C. 20059. E-mail: dws@scs.howard.edu August–September 1994 58A 2 815 816 Copyright © 1994, The Mineralogical Society 1994