HKB
to very distinct erogenous action. Among these we will above all mention the temperature sensitiveness; this will perhaps prepare us for the understanding of the therapeutic effects of warm baths.
Mechanical Excitation.--We must, moreover, describe here the production of sexual excitation by means of rhythmic mechanical shaking of the body. There are three kinds of exciting influences: those acting on the sensory apparatus of the vestibular nerves, those acting on the skin, and those acting on the deep parts, such as the muscles and joints. The sexual excitation produced by these influences seems to be of a pleasurable nature--it is worth emphasizing that for some time we shall continue to use indiscriminately the terms "sexual excitement" and "gratification" leaving the search for an explanation of the terms to a later time--and that the pleasure is produced by mechanical stimulation is proved by the fact that children are so fond of play involving passive motion, like swinging or flying in the air, and repeatedly demand its repetition.[20] As we know, rocking is regularly used in putting restless children to sleep. The shaking sensation experienced in wagons and railroad trains exerts such a fascinating influence on older children, that all boys, at least at one time in their lives, want to become conductors and drivers. They are wont to ascribe to railroad activities an extraordinary and mysterious interest, and during the age of phantastic activity (shortly before puberty) they utilize these as a nucleus for exquisite sexual symbolisms. The desire to connect railroad travelling with sexuality apparently originates from the pleasurable character of the sensation of motion. When the repression later sets in and changes so many of the childish likes into their opposites, these same persons as adolescents and adults then react to the rocking and rolling with nausea and become terribly exhausted by a railroad journey, or they show a tendency to attacks of anxiety during the journey, and by becoming obsessed with railroad phobia they protect themselves against a repetition of the painful experiences.
This also fits in with the not as yet understood fact that the concurrence of fear with mechanical shaking produces the severest hysterical forms of traumatic neurosis. It may at least be assumed that inasmuch as even a slight intensity of these influences becomes a source of sexual excitement, the action of an excessive amount of the same will produce a profound disorder in the sexual mechanism.
Muscular Activity.--It is well known that the child has need for strong muscular activity, from the gratification of which it draws extraordinary pleasure. Whether this pleasure has anything to do with sexuality, whether it includes in itself sexual satisfaction? or can be the occasion of sexual excitement; all this may be refuted by critical consideration, which will probably be directed also to the position taken above that the pleasure in the sensations of passive movement are of sexual character or that they are sexually exciting. The fact remains, however, that a number of persons report that they experienced the first signs of excitement in their genitals during fighting or wrestling with playmates, in which situation, besides the general muscular exertion, there is an intensive contact with the opponent's skin which also becomes effective. The desire for muscular contest with a definite person, like the desire for word contest in later years, is a good sign that the object selection has been directed toward this person. "Was sich liebt, das neckt sich."[21] In the promotion of sexual excitement through muscular activity we might recognize one of the sources of the sadistic impulse. The infantile connection between fighting and sexual excitement acts in many persons as a determinant for the future preferred course of their sexual impulse.[22]