EL. W. Hilgard—Floceulation of Particles. 213 
Carbonate of sedi  eeeee 
Chlorid of sodium ___.._-- aa ke 
Sulphate of podidm. 7. 2 ee 
Trieodi¢ photphatets 9702 ee 1°83 
100°91 
The insoluble part of the aqueous extract gave: 
Carbonate of caleium isi 220505 ci. de oes 1 14°02 
Tri-caleic: :phosphate::cus us susie) vewlea cae. 6 
Ti-magnesic: phosphates :. 26. ssn2s0635-cauceds 5°77 
Lad 
Silica (soluble in Na,CO,)......-. ---.-....-.-- 243 
Tron oxides, alumina, and some clay (by difference) -50°47 
| 100.00 
It will be observed that notwithstanding the presence of 
considerable amounts of neutral sodium and calcium salts, that 
of about 0:08 per cent of carbonate of sodium was sufficient to 
render the soil practically untillable. In this case, as well as 
in that of a very large amount of similar “alkali land” in the 
State, the application of a sufficient amount of gypsum to de- 
compose the alkaline carbonate, produces a surprising change; 
which, on the small scale, can be perceived at once, but in the 
field, naturally requires a season’s tillage to become effective as 
to tilth. It at once prevents, of course, the injury to seeds and 
growing plants arising from the corrosive action of the alkaline 
use of gypsum prevents this loss by rendering the ‘eaten 
Insoluble together with the humus, albeit in suc 
