307. Effect of Tobacco upon Character. Nor does tobacco spare the morals. The tobacco-user is apt to manifest a selfish disregard of the courtesies due to others. He brings to the presence of others a repulsive breath, and clothing tainted with offensive odors. He poisons the atmosphere that others must inhale, and disputes their rights to breathe a pure, untainted air. The free use of tobacco by young people dulls the acuteness of the moral senses, often leads to prevarication and deceit in the indulgence, and is apt to draw one downward to bad associates. It is not the speed but the direction that tells on the future character and destiny of young men. Additional Experiments. Experiment 132. _To illustrate the cooperation of certain parts of the body._ Tickle the inside of the nose with a feather. This does not interfere with the muscles of breathing, but they come to the help of the irritated part, and provoke sneezing to clear and protect the nose. Experiment 133. Pretend to aim a blow at a person’s eye. Even if he is warned beforehand, the lids will close in spite of his effort to prevent them. Experiment 134. _To illustrate how sensations are referred to the ends of the nerves_. Strike the elbow end of the ulna against anything hard (commonly called “hitting the crazy bone”) where the ulna nerve is exposed, and the little finger and the ring finger will tingle and become numb. Experiment 135. _To show that every nerve is independent of any other._ Press two fingers closely together. Let the point of the finest needle be carried ever so lightly across from one finger to another, and we can easily tell just when the needle leaves one finger and touches the other. Experiment 136. _To paralyze a nerve temporarily_. Throw one arm over the sharp edge of a chair-back, bringing the inner edge of the biceps directly over the edge of the chair. Press deep and hard for a few minutes. The deep pressure on the nerve of the arm will put the arm “asleep,” causing numbness and tingling. The leg and foot often “get asleep” by deep pressure on the nerves of the thigh. Experiment 137. Press the ulnar nerve at the elbow, the prickling sensation is referred to the skin on the ulnar side of the hand. Experiment 138. Dip the elbow in ice-cold water; at first one feels the sensation of cold, owing to the effect on the cutaneous nerve-endings. Afterwards, when the trunk of the ulnar nerve is affected, pain is felt in the skin of the ulnar side of the hand, where the nerve terminates. Chapter XI. The Special Senses. 308. The Special Senses. In man certain special organs are set apart the particular duty of which is to give information of the nature of the relations which he sustains to the great world of things, and of which he is but a mere speck. The special senses are the avenues by which we obtain this information as to our bodily condition, the world around us, and the manner in which it affects us.