NATIONAL MUSEUM OF VICTORIA 
JOURNAL OF THE ROYAL SOCIETY 
OF WESTERN AUSTRALIA. 
Volume XXVII. 
1.— RESULTS OF A MICROSCOPIC STUDY OF SOME 
SOIL COLLOIDS. 
JTy W. F. Cole. 
Read 13th August, 1940 ; Published 14th November, 1941. 
INTRODUCTION. 
In tv o previous pu})lieatious (1) and (2) -I. Shearer and the author have 
doserib(Ml the X-ray analysis of some soil colloids from Western Australia 
and Tasmania. In this paper an account is given of a microscopic examina- 
tion of these soil colloids. 
In the lirst jnihlication cit(xl, the crystalline eonti'nt of colloid separations 
(effective diameter 2^ and less) from two soil samples from the Salmon Gums 
district in Western Australia was dotormiiu^d. These two samples, designattnl 
as A 1340 and A 1351, represent the subsoil and dtH'p subsoil respectively. 
In the S(>cond publication cited, the crystalline content of colloid separa- 
tions (etfective diameter l-4p, and less) from four soil samples from Tasmania 
was determined. The details rega.r<hng the source of these four sampU^s 
ar<‘ : - 
55! and 500 Colloid separatitms from soils from Jllawarra in northern 
Tasmania ; 
499 Colloid separation from a basaltic soil of north-west 
Tasmania ; 
222 Colloid separation from a soil from the Huon valley in 
soutlun-n Tasmania. 
The linal X-iay conclusions rtigarding the composil ion of tlu^se soil colloid 
fractious are eontaine<l in T’able 1. T'he Ua’ins “ kaolinite," ’■ montmorill- 
onito,” anti " mica ” have been ustxl in this talile and in the remuintler of this 
paptu’, for brevity, to tlosignate a mineral btTonging to the kaohnite grouji, 
the mt>ntmorillonite group and the mica grou]) respectively. This is lu^cessary 
because at present it is not possible to idtsntify minerals within a grou]> in the 
dilfVaction pattern of a soil colloid. 
