Alcohol was administered per rectum and the animals were killed 1/4-4 hrs. after receiving the alcohol. The brains were removed and placed in a refrigerator for a few minutes before slicing. The slices were suspended in either phosphate-Ringer solution of pH 7.4 or in the same solution plus 0.4% alcohol. There was an increased O2 uptake in the brain tissue of those animals which were killed 1/4-1/2 hr. after administration of alcohol and it lasted for about 1 hr. This maximum uptake was followed by a gradual fall. The increase Was greatest in the tissues composed largely of grey matter.