CELLS 9 



vants to do just as the mind tells them. Thus, when the 

 mind wants to walk, all the cells of the legs get themselves 

 under the body and push the body ahead. They do it so 

 willingly that we do not think how hard they have to 

 work. When the mind wishes to stop, it tells the cells of 

 the legs that they need not work any more until it wishes 

 to move again. 



Sometimes it is very hard for the mind to teach the cells 

 to work just as they should and to keep still when they 

 ought. Boys and girls go to school so that they may learn 

 how to make the cells obey the mind. We ought to take 



Water, 12 gallons 



Albumin or gelatine, 20 Ib. 

 Substances of which the body is composed. 



Fat. 10 Ib. 



good care of our bodies because the living cells of which 

 they are composed make such good servants for the mind. 



4. Of what the cells are made: water. About three 

 fourths of each cell of the body is water. Water is found 

 even in teeth and in bone. All animals must have water 

 to drink. Even the driest food, like crackers, has a great 

 deal of water, while other kinds, like meat and potatoes, 

 are nearly three fourths water. In all, a man swallows 

 two or three quarts of water each day. 



5. Albumin. Next to water something which is like 



