ON POTASH AND SODA IN SOILS. 317 
cess, nitrogen is disengaged, either in a free state, or un- 
der some other form than of ammonia — or, that this latter 
gas has not been totally condensed. 
Journ. de Pharm. and Chim. 
ART. LV. — ON A VERY SIMPLE AND CORRECT METHOD 
OF SEPARATING AND DETERMINING THE QUANTITIES 
OF POTASH AND SODA WHEN PRESENT ALONE, OR AC- 
COMPANIED WITH MAGNESIA IN A SOIL OR OTHER 
MIXTURE. By Mr. William Horatio Potter, M. R. A. S. 
Now that it is almost universally acknowledged, both by 
the chemist and the agriculturist, that the alkalies Potassa and 
Soda exercise a very important function in every fertile soil, 
anything tending to simplify the method of separating them 
when occurring together, and the ascertainment of their rela- 
tive proportions, cannot fail to be esteemed by those who are 
interested in either science, as a matter of considerable mo- 
ment. Hitherto it has been reckoned, and that justly, to be 
one of the most difficult problems that chemistry proposes 
for our solution, to discriminate in a simple and correct man- 
ner between the two fixed alkalies Potassa and Soda, and to ef- 
fect their accurate separation. 
The difficulty and complexity of the case, is very much 
enhanced if magnesia is also present, as is very frequently 
the case, and much time is necessary to arrive at a correct 
result. 
Since it has become a matter of prime importance in the 
analysis of soils to estimate the quantity of the alkalies they 
contain, I was led to consider whether a concise, yet exact 
