. Botany; an elementary text for schools. Plants. ROOT-PRESSUKE. The plant thrives in a weak solution. To test this matter, secure a young radish plant (or almost any seedling with several leaves) and insert the roots into a small bottle containing some of the saltpeter solution I, In another bottle place a similar plant with some of the weak solution II. Support the plant in the mouth of the bottle with cotton batting. After standing for a few hours or less it will be noticed that the leaves of the plant in the strong solution begin to w41t, as in Fig, 107. The plant in the weak solu- tion, F

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Image ID: RH91DP
. Botany; an elementary text for schools. Plants. ROOT-PRESSUKE. The plant thrives in a weak solution. To test this matter, secure a young radish plant (or almost any seedling with several leaves) and insert the roots into a small bottle containing some of the saltpeter solution I, In another bottle place a similar plant with some of the weak solution II. Support the plant in the mouth of the bottle with cotton batting. After standing for a few hours or less it will be noticed that the leaves of the plant in the strong solution begin to w41t, as in Fig, 107. The plant in the weak solu- tion, Fig. 108, is rigid and normal. This further indicates that the growing plant is so constituted as to be able to make use of very dilute solutions only. If we attempted to feed it strong fertilizer solutions, these strong solutions, instead of being absorbed by the plant, take water from the latter. causing the plant to tvilt. 145, The farmer or gardener knows that he can injure or even kill his plants by adding too much plant-food. Everyone recognizes the value of wood ashes as a ferti- lizer ; but no one would dare water his valuable plants with lye, or sow his choice vegetable seeds on an ash bank, however well it might be watered. If there is a potted plant at hand which is of no value, remove some of the soil, add considerable wood ashes, water well, and await the result; or give it a large lump of nitrate of soda. 146. ROOT-PRESSURE.—TAe activity of the root in absorb- ing water gives rise to considerable force. This force is known as root-pressure. The cause of this pressure is not well understood. The pressure varies in different plants and in the same plant at different times. To illustrate root-pressure, cut off a strong-growing small plant near the ground. By means of a bit of rubber tube,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may n