422 A. JB. Lyons — Composition of Hawaiian Soils. 



wholly destitute of clay, and contain comparatively little 

 organic matter."^ The mineral constituents requisite for plant 

 food are present in extraordinary abundance, especially the 

 phosphoric acid, and yet these soils may be rather easily "ex- 

 hausted " by loss of their organic matter. 



Table I. Analyses of Hawaiian Soils. [Mineral Constituents,*] 











New, from lava only partially 



Old. from 



thoroughly disin- 









disintegrated. 



tegrated ancient fava. 





i 





2-" 



.«* 







i==5' 



3 







■s 











0; p 



-55 



1 





0"^ 



.7; c4 



a 



% 



of 



p 





0.0 



(SW 



^a 



So 



WW 



WW 



OW 



y\ 



w 



lo 



AlaOst 



22-79 



12-97 



23 97 



23-69 



2209 



17-84 



23-53 



27-48 



29-06 



26-86 



Fe^Os 



24-73 



10^93 



18 78 



29^12 



44-85 



32-13 



34-86 



20-31 



24-54 



29-72 



MnO 



•20 



-03 



•29 



•46 



•10 



•29 



-34 



-15 



•u 



-18 



CaO 



6-47 



3 44 



5 70 



•74 



•09 



-41 



-66 



•39 



•38 



-29 



MgO 



3-62 



•73 



1-43 



1^81 



•19 



•61 



1-C7 



-23 



•28 



•74 



NasO 



1-07 



•71 



•19 



1^07 



•33 



•17 



•33 



•34 



•34 



•22 



K2O 



•74 



•19 



•39 



•58 



•21 



•37 



•38 



-51 



•43 



•16 



P2O5 



2-92§ 



•48 



6^47Tr 



-36 



•40 



•49 



•76 



•10 



•15 



-27 



SO3 



•18 



•05 



•27 



•10 



-16 



•11 



•49 



-07 



•06 



•08 



Soluble SiOa, etc. 



3-23 



res 



2-43 



j 42-48 



7-20 



4-69 



5-45 



j 50-01 



1 44-69 



531 



Insoluble 



36-20 



68-791 



39-72 



24-39 



42-98 



3309 



37-24 



Organic and ^ 























combined [• 



15-10 



14-94 



29-46 



11-88 



34-30 



14-40 



40-80 



16-06 



17 09 



19-77 



Water:): ) 























* Constituents dissolved by boiling two hours with hydrochloric acid, sp. gr. 1-15. 



f Figures except in last line are percentages of the ignited soil. 



X Per cent, of soil dried at 100° 0. 



§ Phosphoric acid in soils from this region ranges from 1-2 to 2-9 + ^ of ignited soil. 



II Contains much undecomposed silicate. 



^ Phosphoric acid in soils from this region ranges from 2-5 to 6*5 per cent, of ignited soil. 



** Contains cobalt. Most of the soils contain copper, some of them chromium. 



IS'o. 1 is derived from a coarse volcanic gravel (lapiili), 

 thrown out in an eruption so recent that except within a few 

 decimeters of the surface it remains as black and fresh-looking 

 as it ever was. If this soil is passed successively through 

 sieves having respectively apertures 2"^, l"""" and ^"^"^ in diam- 

 eter, the first will screen out chiefly fragments of undecom 

 posed gravel, while the second and third will retain coarse 

 sand which will be found to consist almost wholly of crystals, 

 mostly superficially oxidized, of chrysolite. A finer, heavy, 



* Owing to the absence of clay, the organic matter present in such soils is 

 liable to be in a remarkable degree combustible. 



