288. What causes the horny appearance of the nails? Describe the root of the nail in its relation to the sensitive and the scarfskin. Upon what does the nail rest? What is its appearance? What is the lunula? Why is it lighter than the rest of the nail? How does the nail increase in length? In thickness? Where is the greatest thickness? How does the growth of the nail during disease compare with its growth in health? 289. How long does it take the thumb nail to grow from its root to its free extremity? The great toe? Give general rules for the care of the nails. How does physical cleanliness promote moral purity? What does its neglect indicate? 290. What especial care should be taken in regard to the feet? Why? Are baths a modern refinement? What can you say about the ancient Greek and Roman baths? What constitutes the value of the Turkish bath? 291. What class of people should never use this bath? To what class of invalids is it particularly beneficial? Is sea bathing advisable for persons of all ages? How should an inexperienced sea bather begin? When should the sea bath be taken? 292. How long should a delicate person remain in the water? State the danger of bathing when overheated. Under what conditions of body and of temperature should sea or river bathing be avoided? Why? Give illustration of the English soldier. How should the temperature of the water, in bathing, compare with that of the air? Of the body? 293. Describe the bathers' cramp. What are its causes? What precaution should be used by bathers in regard to the mouth and ears? Why? 294. How can a person who does not know how to swim, save himself from drowning? 295. What are the advantages of woolen clothing? Why is it particularly desirable in malarial countries? What double purpose does woolen clothing serve in semitropical climates? 296. Does the warmth of clothing depend on its weight? What errors are often made and with what effect? State what is said in regard to poisonous dyes in wearing apparel. Give illustration. 297. What effect has uncleanly attire on the health? Does this apply to outer as well as under garments? RESPIRATION AND THE VOICE. 73. Name the organs of respiration and the voice. Describe the larynx. The epiglottis. The œsophagus. What is meant by food "going the wrong way"? 74. Describe the vocal cords. Their use. How is sound produced? 75. How are the higher tones of the voice produced? The lower? Upon what does loudness depend? A falsetto voice? What is the cause of the voice "changing"? What is speech? Is the tongue necessary to speech? Illustrate. (See also page 298.) 76. What is vocalization? How are talking machines made? 77. How is _a_ formed by the voice? What is _h_? Difference between a sigh and a groan? What vowel sounds are made in laughing? Does whistling depend on the voice? Tell how the various consonants are formed. What are the labials? The dentals? The linguals? What vowels does a child pronounce first?