sulphate--prophetes.ai

sulphate, n. Chem.
  (ˈsʌlfeɪt, -ət)
  Also sulfate, sulphat.
  [ad. F. sulphate (De Morveau, etc. Nomenclature chimique, 1787), ad. mod.L. sulphātum (sc. acidum acid), f. sulphur: see sulphur, -ate¹ 1 c.]
  1. A salt of sulphuric acid: usually with term indicating the base, as sulphate of ammonia, sulphate of lime, potassium sulphate.

1790 Kerr tr. Lavoisier's Elem. Chem. 224 Hence the neutral salt in which the metal is least oxydated must be named sulphite, and that in which it is fully oxydated must be called sulphat. 1791 W. Hamilton Berthollet's Dyeing I. i. i. iii. 63 Sulphat of copper. 1794 Phil. Trans. LXXXIV. 395 Sulphate of iron (green vitriol). 1799 Med. Jrnl. I. 87 Epsom salts, or sulphat of Magnesia. 1809 Phil. Trans. XCIX. 151 The sulfate of potass decomposes the phosphate of barita. 1815 J. Smith Panorama Sci. & Art II. 470 The sulphates are in general crystallizable. 1831 Davies Mat. Med. 331 The sulphates of zinc and copper..are occasionally used as powerful emetics. 1866 Roscoe Elem. Chem. ix. 89 Hydrocyanic acid mixed with water distils over, leaving potassium sulphate in the retort. 1877 Huxley Physiogr. 120 Such permanent hardness [of water] is due to the presence of sulphate of lime. 1890 F. Taylor Man. Pract. Med. 747 Sulphates.—These are precipitable by barium chloride.

attrib. 1803 Med. Jrnl. X. 499, I have tried the sulphat of soda poultice. 1856 Orr's Circ. Sci., Pract. Chem. 76 The sulphate solution. 1884 Knight Dict. Mech. Suppl. 874/1 Sulphate of Mercury Battery.

2. ellipt. = Sodium sulphate. Also attrib.

[1879 Cassell's Techn. Educ. IV. 355/1 The manufacture of soda ash,..the..sulphate, sulphite, and others.] 1900 Westm. Gaz. 29 Dec. 9/2 A fire at the sulphate works of the West Hartlepool Gas Company.

3. sulphate ion, the ion SO₂^2—; sulphate process Paper-making, a method of manufacturing a tough brown paper involving the digestion of wood chips by sodium hydroxide and sodium sulphate to form the pulp; so sulphate pulp; cf. Kraft; sulphate-reducing a. Biol., (of a process or micro-organism) bringing about the reduction of sulphate ions to sulphur; spec. applied to bacteria of the genera Desulphovibrio and Desulphatomaculum, which do this as part of their respiratory metabolism.

1902 G. S. Newth Text-bk. Inorg. Chem. (ed. 9) xi. 105 SO{pp}₄, in the same way, stands for the *sulphate ion, with its two negative charges. 1978 J. R. Holum Org. & Biol. Chem. xix. 411 The sulfur dioxide is then oxidized to sulfate ion, which is excreted by the kidneys.

1894 G. Clapperton Pract. Paper-Making iv. 32 The former [process]..employs a solution of sodium compounds containing a large percentage of sulphate of soda, and is known as the *sulphate process. 1963 R. R. A. Higham Handbk. Papermaking v. 98 There are three basic alkaline processes, which are: Soda process, Sulphate (Kraft) process, Pomilio process. 1974 Sci. Amer. Apr. 55/1 Most soda pulp mills changed over to the kraft process (which is also often called the sulfate process).

1907 G. Clapperton Pract. Paper-Making (ed. 2) iv. 36 During recent years the demand for ‘*sulphate’ pulp has increased largely, owing to the development of ‘Kraft’ brown paper. 1962 F. T. Day Introd. Paper ii. 19 The wood chips are cooked in digesters in a solution of caustic soda to produce soda pulp, or with a mixture of caustic soda and sulphate of soda to produce sulphate pulp. 1966 F. E. Dean Paper ii. 36 Unbleached sulphate or ‘kraft’..pulp..is used mainly for tough wrapping paper.

1926 Science 1 Jan. 24/1 The oil-field waters in which the *sulphate-reducing bacteria occur are similar in general composition to seawater. 1954 New Biol. XVII. 67 Vastly greater amounts of sulphide are formed in nature by a single group of micro-organisms called the sulphate-reducing bacteria... Their sulphate-reducing process corresponds to the respiration of more normal organisms. 1979 Arch. Microbiol. CXXI. 261/1 Some sulfate-reducing bacteria are able to utilize colloidal sulfur as respiratory substrate.

Hence ˈsulphate v. intr., to become sulphated.

1888 D. Salomons Managem. Accumulators (ed. 3) v. 58 If the positives sulphate the surface becomes very hard. 1898 A. Treadwell Storage Battery 240 The plates will be found to sulphate more rapidly, and the sulphate will be harder to reduce.