What is the journey of the blood to and from the heart to the different parts of the body called?--"The circulation of the blood." What is the circulation of the blood?--"The circulation of the blood is its journey from the heart to the different parts of the body, and from the different parts of the body back to the heart." How often does this circulation take place?--"Once in from three to eight minutes, according as the heart beats fast or slowly." What kind of blood is necessary to health?--"Pure blood." How should the blood circulate?--"Freely, all the time." What do you mean by freely?--"Without anything to hinder." What is necessary for the free circulation of the blood?--"I must wear clean clothing; I must exercise in work or play; I must keep my body warm." How does tight clothing hinder the free circulation of the blood?--"By pressing upon the arteries and veins; and when about the waist, causing the ribs and other parts of the body to press upon the heart." How does exercise help the free circulation of the blood?--"Exercise makes the heart beat faster, which causes the blood to more faster through the arteries and veins." Why does keeping the body warm help the circulation of the blood?--"Because the blood moves faster when it is warmest; cold chills the blood, and makes it move slowly." What harm do alcoholic liquors do to the heart?--"They make it tired, and sometimes wear it out." In what way do they make it tired?--"They make it beat too fast." Why does it beat too fast?--"Because it is hurrying to drive the alcohol out of the body." In what other way do alcoholic liquors hurt the heart?--"They produce disease in it." Tell one way by which the heart becomes diseased through alcoholic liquors?--"Alcohol softens the fibres of the muscles of the heart, and fills them with fat." What harm does this do to the heart?--"It makes it too weak to do its work, which is to pump the blood through the body." What sometimes happens when the heart is thus weakened?--"It stops beating, which causes sudden death." What harm does alcohol do to the blood?--"It uses up the water of the blood; it destroys the goodness of the red part; it makes the blood thin, impure, and unfit to do its work." See Appendices on Alcohol and Tobacco. * * * * * [Illustration: THE LUNGS.] 1, 2, the larynx, the upper part of the windpipe. 3, the windpipe, or trachea. 4, where the windpipe divides to right and left lungs. 5, the right bronchial tube. 6, the left bronchial tube. 7, outline of the right lung. 8, outline of the left lung. 9, the left lung. 10, the right lung. * * * * * PART IX. FORMULA FOR THE LESSON ON THE LUNGS AND RESPIRATION. 1. My lungs are the bellows or breathing machines of my body.