It will be said that when a person thinks, his eyes show his thoughts. When he is sad, his eyes and eyebrows and his forehead change; and when he is glad, the eyes and the forehead smile. We may keep back our smile, but the forehead smiles. If we think very much, our brain becomes tired. Sometimes a feeling of depression comes, and a heaviness, especially in the chest and in the left side. If a joy comes, a feeling of lightness is felt in the heart. This is because, as thought has its organ, the brain, so the heart is the organ of feeling. With the blood, it sends its vibrations to every pore and every atom of the body.