r million of
water, and the Rhine eight parts per million. Some idea of what this
amounts to per annum may be obtained by the statement that "the Rhine
discharges daily 220 tons of saltpetre into the ocean, the river Seine
270, and the Nile 1100 tons."--(Storer's Agric. Chem., vol. i. p. 318.)

NOTE VII. (p. 142).

EXAMPLES OF DECREASE OF NITROGEN IN ROTHAMSTED SOILS.

--------------------------------------+----------------
| Nitrogen in
| 1st 9 inches.
--------------------------------------+----------------
| Per cent.
Old pasture | 0.250
Arable land in ordinary culture | 0.140
Wheat unmanured, 38 years | 0.105
Wheat and fallow unmanured, 31 years | 0.096
Barley unmanured, 30 years | 0.093
Turnips unmanured, 25 years | 0.085
--------------------------------------+----------------

MANURING, PRODUCE OF WHEAT, AND ALTERATION IN THE COMPOSITION OF THE
SOIL IN BROADBALK FIELD, ROTHAMSTED, FROM 1865 TO 1881.

-----+----------------------------------+----------------+----------------------
| | Average | Nitrogen per acre
| | produce | in 1st 9 inches
Plot.| Manures per acre, | per acre. | of soil.
| annually applied, +-------+--------+------+-----+---------
| 16 years, 1865-81. | | | | | Gain or
| |Dressed| Total |1865. |1881.| loss in
| |grain. |produce.| | |16 years.
-----+----------------------------------+-------+--------+------+-----+---------
| | bush. | lb. | lb. | lb. | lb.
3 |Unmanured |11-7/8 | 1715 | 2507 |2404 | -103
5_a_|Mixed mineral manure |12-3/4 | 1963 | 2574 |2328 | -246
10_a_|Ammonium salts, 400 lb. |17-7/8 | 2881 | 2548 |2471 | -77
11_1_|Ammonium salts, with | | | | |
| superphosphate |23-1/4 | 3856 | 2693 |2676 | -17
7_a_|Ammonium salts, with mixed mineral| | | | |
| manure | 28 | 4993 | 2829 |2908 | +79
9_a_|Ni