1) The total heat of neutralisation of most of the usual acids and bases (strong and weak) is liberated within a period of less than 0*01 second. (2) The reactions of carbonic acid with alkali, and of bicarbonate with acid, however, involve heat changes which under appropriate conditions arc spread out over periods of considerably more than 0-01 second. The buffering reactions of glycine and the blood proteins were also studied in a preliminary manner, on account of the physiological interest

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... these pro cesses. In all cases it was found that the heat changes of the reaction were completed (or almost completed) within 0-014 second, as shown by the agree ment between the temperature changes observed to have occurred within 0-014 second and the total temperature changes calculated from the heat of the reaction, as measured by other observers. The physiological and physico chemical implication of these results is discussed. A single experiment on the reaction between carbon monoxide and haemo globin showed that the heat accompanying this reaction was spread out over a period of 0 • 05 second. Further applications of the method are foreshadowed, if and when success has been obtained in extending the accuracy of the temperature measurements from its present limit of 0-001° C. to a further place of decimals, viz., 0-0001° C. (Abstract.) A thermoelectric method is described by which the difference of vapour pressure between two solutions, or between a solution and the pure solvent, can be measured. The principle involved is simply that of a differential wet-bulb thermometer of high sensitivity. A reading is obtained in 30 to 45 minutes and the average error of a single observation is of the order of If per cent, of the difference read.