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
Big Oil Big Oil Big Oil is a name used to describe the world's six or seven largest publicly traded oil and gas companies, also known as supermajors. The supermajors are considered to be BP plc, Chevron Corporation, ExxonMobil Corporation, Royal Dutch Shell plc, Total SA and Eni SpA, with Phillips 66 Company also sometimes described in the past as forming part of the group. The term, analogous to others, such as Big Steel, that describe industries dominated by a few giant corporations, was popularized in print from the late 1960s. Today it is often used to refer specifically to the seven