has been found that it makes a constituent of plants, the quantity
of which contained in them diminishes in proportion to their culti-
vation. It always indicates its presence in soils by the presence of
Chlorine, and is also supplied in its combination with Chlorine.
The result of analyses made by Boussingault and Fresenius may
finally give an idea how much of Potash, Soda and Silicic Acid,
is removed from one acre by a potato crop:

Potash. Soda. Silicic Acid.
Tuber 10 tons, contain of 110             7             11 lbs.

Top 2 " "              4             2            60 lbs.

Total amount of 114             9            71 lbs.

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