420 Scientific Intelligence. 
out any result the more sensibly. Some of the soils were also limed, 
but, while in the plastered soils a decided quantity of potash was made 
soluble in cold water, in the limed soils no such effect was produced. 
‘The subjoined table includes Dehérain’s results :— 
Grammes of potash extracted by cold water from | kilog. of air-dried soil. 
From the, From the F 
Soils. ae plastered Difference. pipes 
Black earth of Russia, Tschernosem, 0:048 | 0126 | +0089 | 4 months. 
“ 0-048 | 0-140 | +0092 | 15 days 
5 0-048 | 0-288 | +0240 1 month, 
Z 0.048 | 0428 | +0380} 14 “ 
Black earth, another specimen, 0128 | 0-138 | +0010 | 1 : 
Soil from Chapelles, 0917 | 0115 | +0098 1 
z Verclives (asparagus bed), 0-487 | 0556 | +0069; 1 
2s Rio-Parana, 0003 | 0067 0°064 1 ig 
oo ™ ~@ Sologne, 0°192 | .0°202 | +001 1 # 
“ Jardin des Plantes, 0046 | 0°355 | +0309 | 24 hours. 
The above experiments were made on such soils as happened to be at 
hand. Other trials were afterwards instituted on such soils as experience 
had taught were either considerably benefitted or quite unaffected by 
plastering, The results were as follows :— 
| _Grammes of potash extracted by cold water from 1 kilog. of air-dried soil. 
i Potazh in Potash in the’ Duration of 
Soils. thenormal| plastered | Difference.| the experi- 
soil. soil. ment. 
Soil from Eragny—never plastered. 0-084 
me Ifo: i 0082 
Ai 
Gueritaude—plastered with 
great advantage, traces. 0°105 0-105 12 hours. 
= Gueritaude, another specimen,! traces. 0°192 0-192 oh fe 
gypsum acts by liberating potash, and explains why wood-ashes are 
if the latter were not occupied by vegetation. “ 
In regard to the mode in which gypsum favors the solubility of potash, 
Dehérain refers to the experiments of Huxtable & Tho 
-arbonate of potash, the result was that 
peli ob ih while sha: plaster’ 
