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
What Is Life early June. The same core of musicians – Bobby Whitlock, Carl Radle, Jim Gordon, Bobby Keys and Jim Price – would similarly elevate other "All Things Must Pass" tracks such as "Awaiting on You All", "Art of Dying" and "Hear Me Lord". The recording is defined by Harrison's descending, fuzztone guitar riff, which also serves as the motif for the chorus.<ref name="Unterberger/AM">Richie Unterberger, "George Harrison 'What Is Life'", AllMusic (retrieved 22 February 2012).</ref> The track opens with this riff, which is then joined by Radle's bass and "churning" rhythm guitar from Clapton, before Gordon's drums bring the full band in.