358 



H. I, JENSEN. 







Table C— Water Soluble. 







No. 



Total Solids 

 including 



colloidal clay 

 Per cent. 



Salt. 

 NaCl 



Per cent. 



Alkalinity 

 as Na 2 C0 3 



Per cent. 



Total Solids 

 without 



colloidal clay 

 Per cent. 



Lime 

 CaO 



Per cent. 



Sulphune 

 Acid 

 H 2 S0 4 



Per cent. 



4 

 5 

 6 

 9 

 11 

 15 



•154 



•106 

 •100 

 n.d. 

 •8ti3 



•023 

 012 

 •041 

 •006 

 •058 



•069 

 •005 

 •010 

 trace 

 •040 



•058 

 •103 



trace 



absent 



No. 4 = Belar gilgai hummock, Yarrie Lake. No. 5 = Belar gilgai 

 hollow, Yarrie Lake. No. 6 = Cleared belar gilgai, Yarrie Lake. No. 

 9 = Belar gilgai, Alexander's, Yarrie Leke. No. 11 = Brigalow gilgai, 

 Trindall'e, Brigalow Creek. No. 15 = Red gilgai belt, brigalow and 

 wilga, Cubbo-Cuttabri track. 



Appendix I. 



Two open cylinders, A and B, each If inches in diameter, 

 were closed at one end with a piece of muslin, and were 

 filled with coarsely powdered soil to a depth of 5J- inches 

 and 5£ inches respectively. In A was placed gilgai soil 

 (No. 11), in B black soil of alluvial origin (Namoi alluvial). 

 Bach cylinder was thoroughly drenched with water until 

 the soil in it was saturated. 



The soil in A expanded to 6f fnches and then became 

 puddled, that in B expanded to 5|- inches. The soil was 

 then allowed to drain, thereafter it was dried at 100° 0., 

 removed from the cylinders, broken up to the same degree 

 of fineness as before, and then replaced in the cylinders 

 and measured. The soil in A had shrunk to 5 inches and 

 that in B to 5^ inches. 



The difference in volume between the saturated soil and 

 the same dried at 100° O. was then calculated. The result 

 obtained gave an expansion on wetting of 37*3% for the 

 gilgai soil and an expansion of 17*1% for normal Namoi 

 alluvial. The expansion of gilgai soil on wetting is there- 

 fore more than twice as great as that of black alluvial soil. 



