CONTENTS 



Lessons marked with an asterisk [*] are somewhat more difficult than the others, and 

 may when desired be deferred or omitted. Usually this will be unnecessary. 



PAGE 



I. THE HUMAN BODY . . . . 1 



The hand. The mouth. The eye. 



II. HEAT IN RELATION TO THE HUMAN BODY . 9 



Combustion. Ventilation. Respiration. The human 

 body as an engine. Regulation of the body temperature. 



III. HEALTH AND WELL-BEING ... 19 



Keeping well. Infection. Sanitation. The water supply 

 and health. General health problems. Life, growth, rest, 

 and recreation. Stimulants and narcotics. General science 

 and right living. 



IV. MATTER AND FORCE . ... 38 

 Some properties of matter, and changes in matter due to force. 



V. WATER AND ITS USES ... 41 



Some properties of water. Vaporization and condensation. 

 Heat of vaporization and of fusion. Solution, absorption, 

 and diffusion. Osmosis in the body and in plants. Study of 

 a stream. Valley formation and surface erosion. 







VI. THE ATMOSPHERE .... 53 



Some properties and uses of air. Pressure exerted by the 

 atmosphere. Applications of atmospheric pressure. Causes 

 of change in atmospheric pressure. Currents in the atmos- 

 phere. Areas of high and low pressure.* 



