This equipment grant will allow the acquisition of an automated carbon, nitrogen, and sulfur analyzer to be used primarily in an ongoing program of oceanic tracer and flux analyses at Rice University. The oceanic pathways of carbon, nitrogen, and sulfur are indicators of significant biogeochemical processes with global implications, and have assumed crucial positions in developing studies of global change. This system will replace an almost thirty-year old instrument that can no longer be overhauled or kept in operating condition, and will greatly expand the institutional research capabilities by allowing the analysis of much smaller samples than had heretofore been possible. No equivalent instrument is presently available on the Rice University campus, and the new system will support the efforts of approximately six research groups at Rice University and at the University of Houston. Rice University is committed to providing 50% of the total cost of the new instrumentation in a matching grant.