PRACTICE VII 



FLOCCULATING EFFECT OF LIME 



Use four shaker bottles with rubber stoppers. 



In the first put 200 cc. distilled water as a check, in the 

 second 200 cc. of a 0.025 per cent solution 1 of quicklime (CaO, 

 preferably C.P.), in the third 200 cc. of a 0.05 per cent solution, 

 and in the fourth 200 cc. of a 0.1 per cent solution. Add to each 

 3 g. of a heavy clay finely ground in a mortar. Agitate for one 

 hour in the mechanical shaker. 



After shaking take out a drop from the check and 0.1 per 

 cent solution and examine under a microscope with a high power. 

 Make sketches on data sheet of the arrangement of soil particles. 



Then pour some of the contents of the bottles into tubes and 

 whirl in a centrifuge, stopping every two or three minutes to 

 note the effect upon clearness. Whirl for at least ten minutes. 

 Then pour the contents of the tubes back into their respective 

 bottles, shake thoroughly, and set aside. Observe regularly 

 to determine the time required for complete sedimentation in 

 each case. 



Which becomes clear first in the centrifuge ? Why ? 



What application of this principle is made in farm practice ? 



REFERENCES. 



" Soils," Lyon and Fippin, pp. 116 and 352. 



"The Soil," Hall, pp. 38-41. 



"Physical Properties of Soil," Warington, pp. 25-35, especially 



30-32. 

 " The Soil," King, p. 30. 



1 These solutions will be made by the instructor. 



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