Great care should be exercised in the choice of a diaper for infants and the material of which it is made. The diaper should fit easily about the organs which it covers and protects, so as not to cause undue heating or friction of the parts; and immediately after a babe has soiled itself either with urine or from a motion of the bowels, it should be made clean and dry at once to avoid any irritation that would otherwise ensue upon these delicate parts. The material of which the diaper is made should not be stiff or harsh, but very limp, soft and pliable; nor should it be thick and bungling. There are great objections to the use of oil-cloth, rubber or other impervious materials as they prevent the escape of perspiration, urine, fecal matter, etc. As soon as possible, say near the end of the first year, the child should be taught to use its little chair-commode, thus dispensing with the diaper at an early age. This is much better for the sexual organs, is more comfortable for the child and is more healthy; it also favors a more perfect development of the limbs and joints, the hip joints particularly. CHAPTER III. Childhood. Childhood is that portion of life extending from infancy to adolescence, which in boys occurs at the age of fourteen to sixteen years; and in girls at the age of twelve to fourteen years. In very warm climates adolescence is reached some two or three years earlier. Most fortunate the infant who has completed its term of life, thus far, in accordance with the strictest rules of Hygiene, or the laws of health. "In a state of health sexual impressions should never affect a child's mind or body. All its vital energy should be employed in constructing the growing frame, in storing up proper external impressions and in educating the brain to receive them." Unfortunately this state of health is not always attained. Impressions may be exhibited in these organs at a very early age either from inheritance, from improper handling or from some morbid condition of the child that could show itself in no other organ of the body and which, like morbid conditions in general, make their appearance somewhere in the mind or body.