POINSETT COUNTY. 155 
Brick earth at depth of J+ feet, Harrisburg. 
[Dried at 110°-115° C. Brackett & Smith, analysts.] 
Silica (SiO a ) 81. 37 
Alumina (A1 2 3 ) 8. 52 
Iron (Fe 2 3 ) 2. 88 
Manganese (MnO) 1 . 01 
Lime(CaO) 44 
Magnesia (MgO) 50 
Loss on ignition 2. 88 
100. 00 
Air-dried sand in air-dried clay 28. 08 
Analysis of clay from an old clay pit at Harrisburg in sec. 25, T. 11 N., R. 3 E. 
[Sample dried at 110°-115° C. R. N. Brackett, analyst.] 
Silica (Si0 2 ) (free and combined ) 75. 93 
Alumina (A1 2 3 ) 11. 05 
Iron oxide (Fe 2 3 ) 6. 10 
Lime (CaO) ' 67 
Magnesia (MgO) 7G 
Potash (K 2 0) 72 
Soda (Na 2 0) 63 
Phosphoric acid (P 2 6 ) 20 
Loss on ignition 4. 56 
100. 62 
Air-dried sand 37. 62 
The large amount of iron oxide and small amount of lime will give 
a deep red colored product. 
The following analysis was made from the loess brick clay which 
came from the top of Crowleys Ridge, a short distance north of 
Spencer Creek, in Poinsett County: 
Analysis of loess from Crowleys Ridge north of Spencer Creek. 
[Dried at 110 o -115° C. Brackett & Smith, analysts.] 
Silica (SiO,) 85. 83 
Alumina (A1 2 3 ) 7. 50 
Ferric oxide (Fe 2 3 ) 2. 66 
Manganese (MnO) Trace 
Lime (CaO) 32 
Magnesia (MgO) 35 
Alkalies (by difference) 1. 16 
Loss on ignition 2.18 
100. 00 
Air-dried sand in air-dried soil 64. 80 
There is a striking similarity in the appearance of surface clay on 
top of Crowleys Ridge at Spencer Creek and the yellow clay that 
