260 Common Science 



do all of this experimenting. For the salt in his blood 

 turns to solid hard grains, and the dissolved food in 

 the blood turns to dustlike particles. His blood flows 

 through him, a muddy stream of sterile water. The 

 cells of his body get no food, and even before they miss 

 the food, most of the cells shrivel to drops of muddy 

 water. The whole man collapses. 



Plants are as badly off. The life-giving sap turns 

 to water with specks of the one-time nourishment float- 

 ing uselessly through it. Most plant cells, like the cells 

 in the man, turn to water, with fibers and dust flecks 

 making it cloudy. Within a few seconds there is not 

 a living thing left in the world, and the saltless waves 

 dash up on a barren shore. 



Probably we had better let the SOLUTION switch 

 alone, after all. Instead, here are a couple of experi- 

 ments that will help to make clear what happens when 

 anything dissolves to make a solution. 



Experiment 80. Fill a test tube one fourth full of cold 

 water. Slowly stir in salt until no more will dissolve. Add 

 half a teaspoonful more of salt than will dissolve. Dry the 

 outside of the test tube and heat the salty water over the 

 Bunsen burner. Will hot water dissolve things more readily 

 or less readily than cold? Why do you wash dishes in hot 

 water ? 



Experiment 81. Fill a test tube one fourth full of any 

 kind of oil, and one fourth full of water. Hold your thumb 

 over the top of the test tube and shake it hard for a minute 

 or two. Now look at it. Pour it out, and shake some pre- 

 pared cleanser into the test tube, adding a little more water. 

 Shake the test tube thoroughly and rinse. Put it away 

 clean. 



