I 



CHEMICAL ANALYSES. 185 



Phosphoric acid .07 



Chlorino 37 



Vegetable matter 1.60 



Moisture aud loss 3.00 



100.00 



9. SOIL FKOM PIMAS PLAINS. 



Silica 83.24 



Alumina T.OO 



Peroxide of iron .78 



Oxide of manganese .11 



Lime 1.88 



Magnesia .07 



Potass .37 



Soda .41 



Carbonic acid 1.27 



Sulphuric acid .21 



Phosphoric acid .04 



Chlorine 28 



Vegetable matter 1.24 



Moisture and loss 2.50 



100.00 



10. SOIL FROM DESERT SOUTH OF PIMAS VILLAGES. 



Silica 89.26 



Alumina 6.40 



Peroxide of iron .87 



Oxide of manganese .15 



Lime .44 



Magnesia .33 



Potass .66 



Soda 42 



Carbonic acid 



Sulphuric acid .10 



Phosphoric acid .03 



Chlorine , 30 



Vegetable matter 



Moisture and loss 1.44 



100.00 



These soils have one common source, a decaying, felspar granite rock. The fragments of 

 quartz are rounded and semi-transparent, intermingled with minute crystals of white felspar 

 and brown colored mica ; small particles of amphibole may be seen through the soil when 

 24 U 



