| _Potassium_ | |
Ashes | _Calcium_ | |
| Magnesium | |
| Iron | |
-------------------+---------------------+----------------+
Water | Oxygen | Soil |
| Hydrogen | |
-----------------------------------------+----------------+

Here is a brief description of these chemical elements.

Oxygen, a colorless gas, forms one-fifth of the air.

Hydrogen, a colorless gas, forms a part of water.

Carbon, a dark solid, forms nearly one-half of all organic matter;
charcoal is one of its forms. The lead in your pencil is another
example.

Nitrogen, a colorless gas, forms four-fifths of the air. Found in all
albuminoids.

Sulphur, a yellow solid.

Phosphorus, a yellowish white solid.

Potassium, a silver white solid.

Calcium, a yellowish solid. Found in limestone.