To strenthen your nervous system you have to do the following exercises:
Lean back on a tree – oak, pine or beech – and think about the influences and energies that come from it. Thus you will absorb the magnetism from the tree and it will strenthen your nervous system.
When the wheat begins ti ripe, walk around a field and thus you will get in touch with the inner life of the wheat. This will help you to absorb a certain amount of energy.
Go for a walk early in the morning, one hour before the sunrise, so that the sunrays are upon your back. Then they will operate a beneficial effect over your backbone and then over your sympathetic system and over your brain system and will regulate them.