The subjoined results, selected from Boussingault, exhibit in a tabular form the relative quantity of organic and inorganic constituents in several kinds of herbage compared in several cases with the root or grain. The water was previously driven off by thorough drying:
| Leaves of Mangel-Wurzel. | Root of Mangel-Wurzel. | Potato Tops. | Potatoes. | Pea Straw. | Peas. | Clover Hay. | Wheat Straw. | Wheat. | |
| Carbon | 38.10 | 42.75 | 44.80 | 43.72 | 45.80 | 46.06 | 47.53 | 48.48 | 46.10 |
| Hydrogen | 5.10 | 5.77 | 5.10 | 6.00 | 5.00 | 6.09 | 4.69 | 5.41 | 5.80 |
| Oxygen | 30.80 | 43.58 | 30.50 | 44.88 | 35.57 | 40.53 | 37.96 | 38.79 | 43.40 |
| Nitrogen | 4.50 | 1.66 | 2.30 | 1.50 | 2.31 | 4.18 | 2.06 | 0.35 | 2.27 |
| Ashes | 21.50 | 6.24 | 3.90 | 3.90 | 11.32 | 3.14 | 7.76 | 6.97 | 2.43 |
| 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 | 100.00 |
Subjoined is a table from the same work of the percentage of mineral substances taken up from the soil by various plants:
| Substances Which Yield Ashes. | Acids | Chlorine. | Lime. | Magnesia. | Potash. | Soda. | Silica. | Oxide of Iron, Ammonia etc. | Charcoal, moisture, and loss. | ||
| Carbonic. | Sulphuric. | Phosphoric. | |||||||||
| Potatoes | 13.4 | 7.1 | 11.3 | 2.7 | 1.8 | 5.4 | 51.5 | traces | 5.6 | 0.5 | 0.7 |
| Mangel-Wurzel | 16.1 | 1.6 | 6.1 | 5.2 | 7.0 | 4.4 | 39.0 | 6.0 | 8.0 | 2.5 | 4.2 |
| Turnips | 14.0 | 10.9 | 6.0 | 2.9 | 10.9 | 4.3 | 39.7 | 4.1 | 6.4 | 1.2 | 5.5 |
| Potato Tops | 11.0 | 2.2 | 10.8 | 1.6 | 2.3 | 1.8 | 44.5 | traces | 13.0 | 5.2 | 7.6 |
| Wheat | 0.0 | 1.0 | 47.0 | traces | 2.9 | 15.9 | 29.5 | traces | 1.3 | 0.0 | 2.4 |
| Wheat Straw | 0.0 | 1.0 | 3.1 | 0.5 | 8.5 | 5.0 | 9.2 | 0.3 | 67.6 | 1.0 | 3.7 |
| Oats | 1.7 | 1.0 | 14.9 | 0.5 | 3.7 | 7.7 | 12.9 | 0.0 | 53.3 | 1.3 | 3.0 |
| Oat Straw | 3.2 | 4.1 | 3.0 | 4.7 | 8.3 | 2.8 | 24.5 | 4.4 | 40.0 | 2.1 | 2.9 |
| Clover | 25.0 | 2.5 | 6.3 | 2.6 | 24.6 | 6.3 | 26.6 | 0.5 | 5.3 | 0.3 | 0.0 |
| Pease | 0.5 | 6.7 | 30.1 | 1.1 | 10.1 | 11.9 | 35.3 | 2.5 | 1.5 | traces | 2.3 |
| French Beans | 3.3 | 1.3 | 26.8 | 0.1 | 5.8 | 11.5 | 49.1 | 0.0 | 1.0 | traces | 1.1 |
| Horse Beans | 1.0 | 1.6 | 34.2 | 0.7 | 5.1 | 8.6 | 45.2 | 0.0 | 0.5 | traces | 3.1 |
CHAPTER XIX.
THE ELIMINATION OF WASTE SUBSTANCES.
The expenditures of the human body, or the waste products which arise from the activity of the master tissues, are thrown off by the excretory tissues, as the lungs, the skin, the kidneys, and the terminal part of the intestines.