THOUGHT QUESTIONS. =Shoes.=--=1.= What the faults of shoes may be in size; shape; sole; heel; toe; instep. =2.= Name deformities resulting to skin of foot; nails; joints; arch; ankle; spine. =3.= State effects of uncomfortable shoes on muscular activity; mind and disposition. =4.= State effect of aversion to walking on muscles; circulation. =5.= If a shoe is too loose, it slips up and down at the heel and chafes the skin there; if too tight, there is pressure on the toes, which causes a corn or ingrowing nail. Have your shoes been correct, or have they been too loose or too tight? According to this test, what proportion of people wear shoes that are too tight? =6.= How many sprained ankles have you known among boys; girls? =7.= Why is it that people who grow up in warm climates have high, arched insteps, and short, broad, elastic feet, but people of the same race who pass their childhood in cold climates often have long narrow feet with low arches and sometimes have the deformity called “flat foot”? [Illustration: FIG. 52.--ARCH OF FOOT. It forms an elastic spring.] =Instinct as a Guide for using the Muscles.=--The instinctive feeling called _fatigue tells us when to rest_. There is also a _restless, uneasy feeling that comes over a normal human being when confinement and restraint of the muscles have reached an unhealthy limit. This feeling should not be repressed_ for long at a time. Many, ruled by avarice, ambition, interest in sedentary work, a silly notion of respectability, or a false conception of duty, have repressed this feeling and have lost it. There is then a feeling of languor, and a disinclination to the very activity which health demands. An unheeded instinct is as useless as an alarm clock that has been habitually disregarded. =Exercise and Climate.=--In our warmest states and in the tropics, one hour’s vigorous physical labor a day, combined with the ordinary activities of life, will keep a person in good condition. In the colder states, muscular exertion for several hours is needed daily.