This, of allowing him in what is wrong, is only one of many ways in which the loving mother may offend her child. Through ignorance, or willfulness, which is worse, she may not only allow wrong in him, but do wrong by him. She may cast a stumbling-block in the way of his physical life by giving him unwholesome food, letting him sleep and live in ill-ventilated rooms, by disregarding any or every of the simple laws of health, ignorance of which is hardly to be excused in the face of the pains taken by scientific men to bring this necessary knowledge within the reach of everyone.