+----------------------+-------+--------+--------+-------+---------+-------+---------+----------+--------+
| | | | Ferric | | | |Sulphuric|Phosphoric| |
| |Silica.|Alumina.| Oxide. | Lime. |Magnesia.|Potash.| Acid. | Acid. | Total. |
+----------------------+-------+--------+--------+-------+---------+-------+---------+----------+--------+
| True Coals. | | | | | | | | | |
| Dowlais, South Wales | 39.64 | 39.20 | 11.84 | 1.81 | 2.58 | .. | .. | 3.01 | 98.08 |
| Ebbw Vale, " | 53.00 | 35.01 | .. | 3.94 | 2.20 | .. | 4.89 | 0.88 | 99.92 |
| Konigsgrube, Silesia | 55.41 | 18.95 | 16.06 | 3.21 | 1.87 | 2.05 | 1.73 | 0.36 | 99.64 |
| Ohio | 44.60 | 41.10 | 7.40 | 3.61 | 1.28 | 1.82 | 0.59 | 0.29 | 100.69 |
| | | | | | | | | | |
| Lignites. | | | | | | | | | |
| Helmstadt, Saxony | 17.27 | 11.57 | 5.57 | 23.67 | 2.58 | 2.64 | 33.83 | .. | 97.13 |
| Edeleney, Hungary | 36.01 | 23.07 | 5.05 | 15.62 | 3.64 | 2.38 | 12.35 | .. | 98.12 |
+----------------------+-------+--------+--------+-------+---------+-------+---------+----------+--------+
Water in coal.
The amount of water present in freshly raised coals varies very
considerably. It is generally largest in lignites, which may sometimes
contain 30% or even more, while in the coals of the coal measures it
does not usually exceed from 5 to 10%. The loss of weight by exposure to
the atmosphere from drying may be from 1/2 to 3/4 of the total amount of
water contained.