Iron(II) sulfate was used in the textile industry for centuries as a dye fixative. It is used historically to blacken leather and as a constituent of ink. The preparation of sulfuric acid ('oil of vitriol') by the distillation of green vitriol (Iron(II) sulfate) has been known for at least 700 years. Together with other iron compounds, ferrous sulfate is used to fortify foods and to treat and prevent iron deficiency anemia. Constipation is a frequent and uncomfortable side effect associated with the administration of oral iron supplements. Stool softeners often are prescribed to prevent constipation. Ferrous sulfate was used in the manufacture
Oil wrestling it harder for the wrestler grip one's opponent. This form continued to what is today known as Yağlı Güreş or Turkish oil wrestling. In the Ottoman Empire, wrestlers learned the art in special schools called tekke (), which were not merely athletic centres, but also spiritual centres. Wrestlers oil one another prior to matches as a demonstration of balance and mutual respect. If a man defeats an older opponent, he kisses the latter's hand (a sign of respect for elders in Turkey). Matches are held all over Turkey throughout the year, but in early summer, around 1000 competitors gather in