=The urinary organs.=--The urinary system consists of the following organs: Two (1) kidneys, only one can be shown in the cut. The kidneys are located just above the small of the back and in front of the spinal column, or backbone. The kidneys take up water, waste matter and impurities from the blood. In this way the kidneys help to keep the blood pure. This liquid mixture is called urine. The use of tobacco and strong drink injures the kidneys, and prevents them from doing all the work that they need to do in order to keep the blood pure and the body healthy and strong. As fast as the kidneys form the urine it is carried by two ducts, called the (2) ureters, one leading from each kidney, and emptied into the (3) bladder. Here it is stored until we wish to discharge it from our bodies. The urine is discharged from the body by a duct that leads through the external sexual organ, and this duct is called the (4) urethra. This process of discharging the urine is called urinating. This is a perfectly natural act. There is no more sin in urinating than in shedding a tear. Because of unfortunate training, many boys think of this act as sinful. The words and expressions they have learned for this act have been associated for years with low thoughts. It is for this reason that you should cease to use those false words and expressions and learn to say, “I desire to urinate,” or “I have urinated.” =The sexual organs.=--Some of the sexual organs are on the outside of the body and some are on the inside of the body. Those on the outside of the body are perfectly familiar to all boys. The external organ through which the (4) urethra passes is called the (5) penis. This organ is not shown in the cut, its position being shown by the figure (5). At the end of this organ is a sheath of loose skin, called the prepuce or foreskin. In some boys the prepuce is quite long and tight. When the boys of the Jewish race are eight days old they are circumcised. This act consists in cutting off that portion of the prepuce that extends beyond the head of the penis. The act is performed with a sharp knife and causes but little pain. Ninety millions of Mohammedans practice circumcision. This [Illustration] should be performed on many boys in this country when they are only a few days old. There are a number of reasons for this. Underneath the folds of the prepuce are hundreds of little glands that secrete a substance that should be removed daily with water, or a wet rag. When the prepuce will not glide back over the head of the penis, it cannot be kept clean. In such cases the secretion becomes white and hard and causes irritation. Boys in this condition will often scratch this organ. In many cases, these boys do not get along well in school, they are nervous, have fits and spasms, and this scratching often leads to a bad habit.