school is work of the brain. Work of the brain eats the brain away. Sleep is the chance and laboratory of repair. If a child's brain-work and sleep are normally proportioned to each other, each night will more than make good each day's loss. Clear heads will greet each welcome morn. But if the reverse occurs, the night will not repair the day; and aching heads will signalize the advance of neuralgia, tubercle, and disease. So Nature punishes disobedience. It is apparent, from these physiological considerations, that, in order to give girls a fair chance in education, four conditions at least must be observed: first, a sufficient supply of appropriate nutriment; secondly, a normal management of the catamenial functions, including the building of the reproductive apparatus; thirdly, mental and physical work so apportioned, that repair shall exceed waste, and a margin be left for general and sexual development; and fourthly, sufficient sleep. Evidence of the results brought about by a disregard of these conditions will next be given. FOOTNOTES: [3] Human Physiology, p. 546. [4] As might be expected, the mortality of girls is greater at this period than that of boys, an additional reason for imposing less labor on the former at that time. According to the authority of MM. Quetelet and Smits, the mortality of the two sexes is equal in childhood, or that of the male is greatest; but that of the female rises between the ages of fourteen and sixteen to 1.28 to one male death. For the next four years, it falls again to 1.05 females to one male death.--_Sur la Reproduction et la Mortalite de l'Homme. 8vo. Bruxelles._ [5] Lectures on Diseases of Women. Am. ed., p. 48. [6] "Much less uncommon than the absence of either ovary is the persistence of both through the whole or greater part of life in the condition which they present in infancy and early childhood, with scarcely a trace of graafian vesicles in their tissue. This want of development of the ovaries is generally, though not invariably, associated with want of development of the uterus and other sexual organs; and I need not say that women in whom it exists are sterile."--_Lectures on the Diseases of Women, by Charles West, M.D. Am. ed., p. 37._ [7] Enigmas of Life, pp. 165-8. [8] Tuckerman's Genera Lichenum, Introduction, p. v. [9] Carpenter's Human Physiology, p. 455. [10] Nicholson, Study of Biology, p. 79. [11] Popular Science Monthly, August, 1872, p. 411. [12] Sleep and its Derangements, pp. 9, 10, 13. PART III. CHIEFLY CLINICAL.