SUSPENSION AND SOLUTION 



143 



SETTLING BASINS OF THE ST. Louis WATER PLANT 



Muddy river water is pumped into these basins and is allowed to stand 

 until it loses its heavier sediment (Experiment 64). The combined 

 capacity of these basins is 245,000,000 gallons. 



Experiment 66. Add some salt to the contents of the glass 

 used in the preceding experiment. Arrange a glass funnel with a 

 filter paper in it, as shown in Figure 74. Pour the contents of the 

 glass into the funnel and collect the water 

 that runs through the filter paper. Do the 

 sand and dust run through? Put a little of 

 the filtered water in a watch crystal or in a 

 shallow vessel and allow it to evaporate. Did 

 the salt in solution come through the filter 

 paper? 



Filters of all kinds are used to remove 

 suspended materials from water ; but as 

 was shown in Experiment 65, the sub- FIGURE 74 



