Chem. [f. SULPH- + ION.] The hypothetical radical consisting of one equivalent of sulphur and four of oxygen (SO4).
1868. Miller, Elem. Chem. (ed. 4), II. 186.
1876. Harley, Royle’s Mat. Med., 54. The more oxydisable metals, zinc, iron,… and manganese are dissolved by the dilute acid, hydrogen being liberated, while the Sulphion (SO4) unites with the metal to form a sulphate.
1909. J. W. Jenkinson, Experim. Embryology, 143. The sulphuric acid radicle (sulph-ion) is thus necessary for the proper development of the gut.
