Observations on the variations of pH of brain tissue

IN previous communications [Holmes and Holmes, 1927; Holmes and Sherif, 1932], it has been demonstrated that the amount of lactic acid formed by the excised brain after incubation is dependent, within limits, on the level of the blood-sugar at the time of death, while the lactic acid found in brains which have been rapidly fixed in liquid air is constant in amount and independent of the blood-sugar, except when the latter has been reduced by insulin to a low level. It was thought that it would be interesting to see whether these changes in lactic acid content were associated with any demonstrable change in the PH of the tissue.