290 Note on tlir JJcc/uaiical A/nili/t<i,>< of JJ mints Soils 



Ab. 4 B Ab. B S F 2 A F 2 B G 26 A C 3li A 



Totals 100-7 101-7 US 4 97-1 97-G 97-2 96-8 95-6 104 1 99-7 98-1 99' 



Totals 980 980 98-0 98-0 97-9 980 97-4 97-9 98-3 97-0 



It will be noticed that in every case there is an increase in the amount 

 of clay obtained. Tn other words the effect of the oxidation has been 

 to increase the degree of dispersion of the soil. That this effect was not 

 an apparent increase in the clay owing to higher visco-sity of tJie aqueous 

 solution of the oxidation products was shown by a viscosity determina- 

 tion on a filtrate obtained from an oxidation. The ^^scosity was sensibly 

 the same as for pure water and it may be assumed tliat tlie difference 

 is due to an actual dispersion of complex particles which are not broken 

 uy) in the ordinary method of dispersion. The hydrogen-peroxide dis- 

 persion has of course been effected without preliminary acid treatment, 

 in the case of the soils used. Possibly it might be desirable to include 

 the acid treatment in the case of soils containing much carbonate. It 

 is worthy of remark that the clay hquor obtained by the peroxide method 

 is strikingly different from that obtained by the ordinary method. On 

 agitation, it shows a satin-like effect owing to the reflection of hght 

 from minute crystaUine particles. This effect is not shown by the clay 

 liquor from soils in the ordinary method. Similar results are obtained 

 with fine silt suspensions. It is also noticed that on flocculation of the 

 clay hquor a smaller volume of flocculated material is obtained than in 

 the ordinary method. 



