Several experiments were conducted bearing on the following points: the validity of variations in bodily electrical phenomena as measures of depth of sleep; a closer analysis of the electrical responses of the body with respect to their actual electrical nature, resistance, polarization, potential, etc.; relation of the apparatus and technical procedure to the results obtained. Experiments using a unidirectional current and measuring the apparent bodily resistance failed to confirm the statements of Farmer and Chambers and of Richter that such changes are measures of the quality or depth of sleep. There was no correspondence between the frequency or amount of postural activity during sleep and the electrical changes of the body. Using a method of conductivity measurement which obviated polarization, little or no change was observed in the conductivity of the body during the night. One experiment indicated that about 1/5 of the total resistance of the body lies in the skin. A criticism of the use of single factors as measures or criteria of complicated reactions is offered.