Through condensation of the dream certain constituent parts of its content are explicable which are peculiar to the dream life alone, and which are not found in the waking state. Such are the composite and mixed persons, the extraordinary mixed figures, creations comparable with the fantastic animal compositions of Orientals; a moment's thought and these are reduced to unity, whilst the fancies of the dream are ever formed anew in an inexhaustible profusion. Every one knows such images in his own dreams; manifold are their origins. I can build up a person by borrowing one feature from one person and one from another, or by giving to the form of one the name of another in my dream. I can also visualize one person, but place him in a position which has occurred to another. There is a meaning in all these cases when different persons are amalgamated into one substitute. Such cases denote an "and," a "just like," a comparison of the original person from a certain point of view, a comparison which can be also realized in the dream itself. As a rule, however, the identity of the blended persons is only discoverable by analysis, and is only indicated in the dream content by the formation of the "combined" person. The same diversity in their ways of formation and the same rules for its solution hold good also for the innumerable medley of dream contents, examples of which I need scarcely adduce. Their strangeness quite disappears when we resolve not to place them on a level with the objects of perception as known to us when awake, but to remember that they represent the art of dream condensation by an exclusion of unnecessary detail. Prominence is given to the common character of the combination. Analysis must also generally supply the common features. The dream says simply: _All these things have an "x" in common_. The decomposition of these mixed images by analysis is often the quickest way to an interpretation of the dream. Thus I once dreamt that I was sitting with one of my former university tutors on a bench, which was undergoing a rapid continuous movement amidst other benches. This was a combination of lecture-room and moving staircase. I will not pursue the further result of the thought. Another time I was sitting in a carriage, and on my lap an object in shape like a top-hat, which, however, was made of transparent glass. The scene at once brought to my mind the proverb: "He who keeps his hat in his hand will travel safely through the land." By a slight turn the _glass hat_ reminded me of _Auer's light_, and I knew that I was about to invent something which was to make me as rich and independent as his invention had made my countryman, Dr. Auer, of Welsbach; then I should be able to travel instead of remaining in Vienna. In the dream I was traveling with my invention, with the, it is true, rather awkward glass top-hat. The dream work is peculiarly adept at representing two contradictory conceptions by means of the same mixed image.