229, 230. What is a sense? Name the five senses. To what organ do all the senses minister? If the nerve leading to any organ of sense be cut, what would be the effect? [Footnote: Each, organ is adapted to receive a peculiar kind of impression. Hence we can not smell with, the eyes nor see with the nose. Thus, if the nerve communicating between the brain and any organ be destroyed, that means of knowledge is cut off.] Sometimes persons lose feeling in a limb, but retain motion; why is this? What is the sense of touch sometimes called? Describe the organ of touch. What are the papillæ? Where are they most abundant? [Footnote: If we apply the points of a compass blunted with cork to different parts of the body, we can distinguish the two points at one twenty-fourth of an inch apart on the tongue, one sixteenth, of an inch on the lips, one twelfth of an inch on the tips of the fingers, and one half inch on the great toe; while, if they are one inch on the cheek, and two inches on the back, they will scarcely produce a separate sensation.--HUXLEY.] What are the uses of this sense? What special knowledge do we obtain by it? Why do we always desire to handle any curious object? Can the sense of touch always be relied upon? Illustrate. What is the _tactus eruditus_? Tell how one sense can take the place of another. Give illustrations of the delicacy of touch possessed by the blind. 230-232. Describe the sense of taste. How can you see the papillæ of taste? What causes the velvety look of the tongue? Why do salt and bitter flavors induce vomiting? Why does an acid "pucker" the face? What substances are tasteless? Illustrate. Has sulphur any taste? Chalk? Sand? What is the use of this sense? Does it not also add to the pleasures of life? Why are the acts of eating, drinking, etc., thus made sources of happiness? 232, 233. Describe the organ of smell. State the intimate relation which exists between the senses of smell and taste. Name some common mistakes which occur in consequence. Must the object to be smelled touch the nose? What is the theory of smell? How do you account for the statement made in the note concerning musk and ambergris? What are the uses of this sense? Are agreeable odors healthful, and disagreeable ones unhealthful?