Duration of Exposure (h) 
Figure 3. 
2 3 4 5 10 20 30 40 60 
Concentration (g 2.) of Fullers Earth in Suspension 
Effect of fuller's earth on spot, LCgqg (solid points), LCso 
(open points), and LCj9 (x). Dotted line indicates 48-hour 
exposure, the maximum duration of exposure. 
