.31 | 16.13 | 10.74 | 2.69 |
| leaves | 3.02 | 4.85 | 10.36 | 6.18 | 8.04 |
|Mangold Wurzel, root | 0.52 | 1.65 | 3.14 | 15.23 | 1.40 |
| leaves | 1.46 | 5.89 | 6.54 | 6.92 | 2.35 |
|Carrot, root | 0.51 | 12.31 | 4.26 | 18.00 | 1.11 |
| leaves | 3.43 | 6.21 | 5.08 | 23.15 | 11.61 |
|Kohl-rabi, bulb | 0.38 | 13.45 | 11.43 | 10.24 | 0.83 |
| leaves | 5.50 | 9.43 | 10.63 | 8.97 | 9.57 |
|Cow cabbage, head | 0.77 | 12.53 | 7.27 | 16.68 | 1.66 |
| stalk | 0.41 | 19.57 | 11.11 | 6.33 | 1.04 |
|Poppy seed | 0.41 | 31.38 | 1.92 | ... | 3.24 |
| leaves | 2.14 | 3.28 | 5.09 | ... | 11.40 |
|Mustard seed (white) | 0.39 | 44.97 | 2.19 | ... | 1.31 |
|Radish root | 1.19 | 41.09 | 7.71 | ... | 8.17 |
|Tobacco leaves | 2.18 | 3.24 | 5.09 | ... | 11.40 |
|Fucus nodosus | 0.26 | 1.71 | 21.97 | 6.39 | 0.38 |
|Fucus vesiculosus | 0.35 | 2.14 | 28.01 | 2.20 | 0.67 |
|Laminaria digitata | 0.45 | 1.75 | 7.26 | 15.23 | 1.20 |
+---------------------+-------+------------+-----------+----------+---------+

A simple inspection of this table leads to various interesting
conclusions. It is particularly to be observed that some of the
constituents of the ash are not invariably present, and two at
least--namely, alumina and manganese--are found so rarely as to justify
the inference that they are not indispensable. Of the other substances,
iodine is restricted exclusively to sea-plants, but to them it appears
to be essential. Oxide of iron, which occurs only in small quantities,
has sometimes been considered fortuitous, but it is almost invariably
present, and the experiments of Prince Salm Horstmar leave no doubt that
it is essential to the plant. Its function is unknown, but it is an
important constituent of the blood of herbivorous animals, and may be
present in the plant, less for its own benefit than for that of the
animal of which it is destined to become the food.

Soda appears to be a comparatively unimportant constituent of the ash,
of which it generally forms but a small proportion, although the
in