addition the coarser particles are in the main merely lava fragments 
on their way toward more complete disintegration. These frequently 
show under the microscope the characteristic structure of lava. As 
time goes on the relative proportions of these constituents will 
change, so that eventually a higher percentage of clay and fine silt 
will predominate. The upland soils at the present time frequently 
contain practically no material coarser than silt, with abnormally 
large quantities of clay. The soils are typical laterites, 1 and in 
interpreting the analytical results reported herein it is important 
to bear this in mind. 
CHEMICAL COMPOSITION. 
The chemical composition of these soils, as determined by the use 
of the official methods, is shown in the following table: 
Chemical composition of rice soils. 
District. 
Insoluble 
Potash 
Soda 
Lime 
Magnesia 
(MgO). 
matter. 
(KsO). 
(Na 2 0). 
(CaO). 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
41.69 
0.42 
1.47 
1.99 
9.42 
38.82 
.47 
1.36 
2.48 
9.75 
44.57 
.25 
.46 
.97 
.94 
45.75 
.26 
.36 
.87 
.58 
44.94 
.27 
.34 
.81 
.99 
40.53 
.26 
.45 
.76 
.82 
42. 60 
.16 
.46 
.59 
.49 
37.20 
.14 
.44 
.43 
.26 
38.20 
.06 
.37 
.47 
.31 
50.10 
.10 
.36 
1.22 
.87 
51.15 
.15 
.38 
1.65 
.73 
50.52 
.09 
.24 
1.20 
1.08 
48.30 
.08 
.28 
1.63 
1.54 
37. 82 
.12 
.31 
2.20 
.79 
27.70 
.09 
.32 
2.76 
.78 
42.40 
.16 
.10 
1.16 
2.67 
40.40 
.27 
.10 
.97 
3.35 
47.25 
.19 
.41 
1.18 
2.28 
47.00 
.17 
.34 
.97 
6.98 
45.18 
.15 
.42 
1.26 
1.72 
45. 70 
.14 
.45 
1.38 
2.65 
45.35 
.15 
. 29 
.96 
4.16 
43.30 
.17 
.34 
1.16 
3.07 
Manga- 
nese oxid 
(Mn 3 4 ). 
Ferric 
oxid 
(F 2 3 ). 
OAHU. 
Waikiki: 
Soil 292 
Subsoil 293 
Fort Shafter: 
Soil 332 
Subsoil 333 
Soil 334 
Kailua: 
Soil 337 
Subsoil 338 
Soil 339 
Subsoil 340 
Kaneohe: 
Soil 343 
Subsoil 344 
Waiahole: 
Soil 345 
Subsoil 346 
Kalaunui: 
Soil 347 
SubSbil348.... 
KAUAI 
Hanalei Valley: 
Soil 460 
Soil 461 
Soil 462 
Soil 463 
Soil 464 
Soil 465 
Soil 466 
Soil 407 
Per cent. 
0.27 
.21 
.32 
.30 
.13 
.09 
.27 
.32 
.35 
.09 
1.16 
.02 
.04 
.14 
.23 
.15 
.13 
Per cent. 
18.01 
21.22 
18.84 
18.48 
17.56 
19.01 
19.67 
24.80 
26.15 
11.20 
10.50 
17.25 
16.18 
7.05 
6.44 
16.22 
17.10 
14.82 
18.20 
15. 32 
15.23 
18.16 
15.91 
1 The decomposition of basaltic lavas usually gives rise to soils high in iron and 
aluminum and relatively low in silica, and while the most finely divided particles are 
usually referred to as clay, the name is improperly applied. Recently Ulpiani (Staz. 
Sper. Agr. Ital., 45 (1912) pp. 629-653) suggested that this process be called lateritization 
in contradistinction to kaolinization, which takes place in the decomposition of orthoclase 
feldspars. 
