Soils and Soil-formers.] SUBANTARCTIC ISLANDS OP NEW ZEALAND. 



747 



Most of the analyses of peat have been made with regard to its value as fuel, 

 and not as a soil. The nature of the inorganic constituents present, beyond a bare 

 statement of the amount of ash, has seldom been given. As it is the soil aspect 

 which this report principally deals with, it has been rather difficult to learn any- 

 thing from the literature on peat which would assist to compare soils of the sub- 

 antarctic islands with other vegetable deposits. 



COMPOSITION OF HUMUS AND PEAT-ASH. 



In the accompanying tabular statement the analyses of a few typical island 

 soils have been recalculated to show the percentage of the inorganic constituents, 

 calculated on the ash, in order that they may be compared with peat-ash analyses 

 given by Groves and Thorpe (38), quoted below. The authors say, " It is said that 

 carbonates of the alkalis never occur in peat." The amount of ash in European 

 peats varies from 1 to 33 per cent. 



Analysis 



OF Ash 



(calculate 



i from Total Analysis). 





5 



OS 



05 





CO 

 o 



o 

 00 



809. 

 811. 



c6 

 00 



in 

 a-. 





« 



« 



w 



« 



i4 



w 



M I W 



Ui 



1^ 



Silica (by difference) 



35-80 



46-20 



31-89 



53-74 



43-77 



24-11 



39-91 



51-25 



43-58 



36-19 



Iron-oxides and alumina, and oxides of 



28-87 



14-98 



27-41 



40-76 



29-16 



19-10 



23-31 



36-88 



47-64 



43-85 



rare earths 























Calcic oxide 



3-18 



4-41 



9-92 



0-89 



3-93 



17-19 



9-51 



14-34 



M6 



0-92 



Magnesic oxide 









3-60 



3-24 



14-35 



1-35 



4-96 



13-13 



13-83 



1-34 



0-89 



1-31 



Potassic oxide 









3-81 



3-89 



4-17 



0-85 



1-14 



2-86 



1-84 



1-12 



0-94 



14-00 



Phosphoric anydride . 









0-84 



1-16 



3-91 



0-93 



4-20 



6-20 



4-91 



2-52 



2-56 



1-36 



Sodic chloride 









12-38 



17-05 



5-22 



0-64 



5-21 



6-44 



3-07 



0-69 



0-43 



0-66 



Sodic sulphate 









2-89 



0-77 



1-83 



0-42 



1-90 



8-59 



2-09 



0-31 



0-24 



0-62 



Sodic oxide 









8-63 



8-30 



1-30 



0-42 



5-731 2-38 1-53 



1-65 



2-56 



1-09 



The following is an analysis of three samples of peat-ash from Tuam, west 

 Ireland, with ash varying from 3-69 to 4-81 per cent. ; average, 4-54 per cent. 

 (No. 1 is a light peat from Ballinderry Bog ; No. 2 is a somewhat older peat from 

 Claretuam Bog ; and No. 3 is a light peat from Weir's Bog) : — 



K,0 



NagO 

 CaO 

 MgO 

 AI2O3 



FCoOg 



cr 



SO3 



P2O5 

 CO2 

 Sol. SiO. 

 Insol. . . 



No. 1. 



No. 2. 



No. 3. 



0-813 



3-56 



5-19 



3-66 



0-37 



0-76 



.35-8.5 



34-79 



36-60 



3-17 



3-60 



7-73 



4-42 



2-80 



3-44 



2-56 



6-34 



6-50 



4-32 



0-43 



0-596 



12-86 



19-70 



16-46 



2-19 



3-56 



2-82 



3-25 



6-76 



7-17 



4-74 



3-34 



4-90 



22-92 



12-92 



6-81 



