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SEX IN EDUCATION.
muscles, relieved of all fatigue, and with the extensors more relaxed than the flexors, are undergoing repair of structure, and recruiting their excitability ; and the voluntary nervous system, dead for the time to the external vibration, or, as the older men called it, ‘ stimulus’ from without, is also undergoing rest and repair, so that, when it comes again into work, it may receive better the impressions it may have to gather up, and influence more effectively the muscles it may be called upon to animate, direct, control.” * An American observer and physiologist, Dr. William A. Hammond, confirms the views of his English colleague. He tells us that “ the state of general repose which accompanies sleep is of especial value to the organism, in allowing the nutrition of the nervous tissue to go on at a greater rate than its destructive metamorphosis.” In another place he adds, “ For the brain, there is no rest except during sleep.” And, again, he says, “ The more active the mind, the
* Popular Science Monthly, August, 1872, p. 411.