The personal welfare of each individual depends largely on the efficiency Of his bodily machinery. The effects of mental and moral habits on the health of the body have long been known, but the recognition of the effects of bodily health upon the mind and the moral character is of recent date. Bodily health is readily within the control of either the individual himself or his parents. The modern science Of hygiene and sanitation is founded upon the idea of personal responsibility of each individual for both the transmission and the acquisition of most diseases.