528 APPLIED BIOLOGY 



by placing the patient on his back and regularly (fifteen 

 times a minute) raising the arms above his head. and then 

 gently lowering them to the sides, making the chest-walls 

 move as in natural breathing. For details of this and other 

 methods, see special chapters on " accidents " in books on 

 hygiene. The teacher should give practical lessons on this 

 important topic, selecting one student as patient and another 

 as operator. 



453. Colds in Respiratory Organs. Severe " colds " 

 which are liable to lead to bronchitis (inflammation of bron- 

 chial tubes), pleurisy (inflammation of pleura of lungs), or 

 pneumonia (congestion of blood, with certain poisonous 

 bacteria in the lungs) require medical advice. Chronic con- 

 gestion of nasal membranes leading to the condition known 

 as catarrh should receive medical attention, for a slight opera- 

 tion or special treatment may be necessary to effect a cure. 



For preventing colds see 458 on bathing. One whose 

 skin has been chilled should hasten to restore the normal cir- 

 culation of the skin by exercise, friction, hot drinks, hot bath 

 (with great precaution against more chilling), and in extreme 

 cases by certain drugs which physicians advise. It is dan- 

 gerous to neglect a " cold," especially in its incipient stages. 



DIGESTIVE ORGANS 



454. Teeth. The proper care of the teeth is commonly 

 emphasized in. the books on " physiology " written for ele- 

 mentary schools, and need not be repeated here. The fact 

 that bacteria are largely responsible for dental decay suggests 

 the daily use of antiseptic tooth-powders and mouth-washes. 



455. Hygiene of Eating. The practicable hygiene of 

 digestion for most people is that which suggests the time 

 for eating, and the amount and kind of food. 



The question of the time of meals depends upon other physio- 

 logical demands. A light breakfast and a light lunch are best 



