§ 97. SILT a:n^alysis. 17X 



settled to the bottom ; then draw off the clear supernat- 

 ant liquid from each funnel with a siphon, and transfer 

 each portion of the sediment to a separate evaporating 

 dish, except that the contents of funnels 1 and 2 should be 

 mixed together; dry each portion at 125° C, and weigh 

 it. After this, ignite each one and weigh again, and. 

 thus determine the amount of organic matter in it. 



By this operation the soil is separated into at least five 

 portions, of different degrees of fineness, 



1. The residue on the sieve, 



2. The contents of funnel No. 2, 



3. " " " " No. 3. J. 



4. " " '^ " No. 4. 



5. The sediment deposited from the water that flowed 

 through the whole apparatus, and the still finer portions 

 remaining suspended in the water even after several 

 hours. These two may be separately determined, if it is 

 desired, by collecting, drying, and weighing the sediment 

 that is deposited after several hours, and then estimating 

 the still finer portion that remains in suspension, together 

 with the hygroscopic water of the soil, by the difference 

 between the 30 grms. of soil taken originally, and the 

 sum of these five residues ; then on subtracting from 

 this remainder the hygroscopic water, as determined in 

 another portion of the soil, we have the weight of the 

 sixth portion ; or, the fifth and sixth may be estimated 

 together, in a similar manner, and without collecting the 

 sediment deposited in the beaker. 



To clarify this liquid more speedily, A. Miiller {Jour- 

 nal far Prakt. Chemie, 95,92; Fresenius's Zeitschrift, 

 5, 243) recommends the following process. Prepare a 

 solution of an ammoniacal soap, with the aid of stearic 

 acid, ammonia, and alcohol, add it to the turbid liquid 

 until the mixture gives considerable foam when violently 

 agitated, then acetic acid until the reaction of the liquid 

 is decidedly acid, and stir or shake the whole vigorously; 



