As the members of a given generation age, their instinct of social conservation becomes stronger, which inevitably and necessarily brings them into conflict with the normal attribute of youthâinnovation. Other important theorists of the 19th century were John Stuart Mill and Wilhelm Dilthey.
Plants require more than just water and sunlight to grow. They also require many nutrients found in the soil. One of the most important nutrients required for plant growth is nitrogen. Nitrogen is used to build plant proteins and nucleic acids, including DNA.
Nitrogen is essential for the growth of leaves and stems, and it helps to give plants a rich, green color. If it is lacking, plants will be pale and sickly-looking, and the oldest leaves will look worse than the newer ones.