Presented at Libby-Cockcroft Meeting on Gas Coolant Compatibility, Harwell, Berks, England, April l962. Preliminary studies are reported of the system graphite-carbon dioxide - carbon monoxide under irradiation, using C/sub 14/-labeled gases; particular attention was paid to the deposition reaction. Results are presented for analyses on a series of silica bulbs containing graphite specimens in rod form and filled with C/sup 14/-labeled CO//sub 2/, had been irradiated in a gamma flux. The amounts of CO formed were small (