We may now believe that in the interstitial tissues of the gonads special chemical substances are produced, which, when taken up in the blood stream, charge definite parts of the central nervous system with sexual tension.-Sigmund Freud 5 1 HE INVESTIGATION and measurement of emotions and emotional change constitute a research area that has challenged many but left none triumphant. Also challenged, but humbled by the prospective task, we have been attracted particularly to the general problem of the lack of a quantitative tool in psychiatry and to the specific problem of the need for a method of measuring, with reasonable precision, the extent of emotional change. These interests have involved us in construct selection and formulation of such questions as: What phenomena are to be labeled as typifying a specific emotion and what levels of affective aware-