1. Individual, accidental, ephemeral cases. These can be reduced to a single formula: when two or more states of consciousness have been accompanied by the same emotional state, they tend to be associated with one another. Emotional resemblance unites and intertwines disparate impressions. It is a case of association by resemblance, _but not intellectual_; impressions are associated because they resemble one another in a common emotional colouring, not _qua_ impressions. Examples of this are abundant. L. Ferri (in his _Psychologie de l’Association_, where, by-the-bye, he does not note this emotional law) tells us that one day, being stung by a fly, he suddenly remembered a child seen by him, long ago, when himself very young, on its death-bed. Whence this sudden vision? “In the first place, I was lying on my bed, then I had been stung by a fly, and lastly, the sight of the corpse had caused in me a deep sadness, while, at this same moment, I also happened to be very sad.” Association through emotional identity or resemblance is of frequent occurrence in dreams, as has been already said. I remember, among many others, a dream whose unity, in spite of the apparent incoherence of the association, was due to a general sense of fatigue. A road without milestones stretched before me, of which I was about to complete the last stage; steep mountains kept rising one behind another; my eyes were wearied with trying to catch sight of the longed-for town on the horizon; and every time I wished to inquire the way I had to speak a foreign language which I understand but imperfectly, and in which it is very difficult for me to express myself. I awoke, feeling a general aching and heaviness of all the limbs. Sully relates a dream whose unity consisted in a sense of anxiety and vexation. He was suddenly called upon to give a lecture on Herder; he began by stammering out some generalities; then he was addressed by one of his audience, who suggested difficulties to him; then the entire assembly broke up tumultuously. One of his children, who had seen, for the first time, the great clock at Strasburg, and, after an interval of two days, the Swiss glaciers, dreamed on the following night that the figures of the clock were walking about on the snow. In this case the groundwork of the dream is a feeling of admiration or surprise.