▪ I. sludge, n.
(ˈslʌdʒ)
Also 8 sluge.
[var. of slutch n.]
1. a. Mud, mire, or ooze, covering the surface of the ground or forming a deposit at the bottom of rivers, etc. Cf. sludge v. 6.
| 1649 W. Blithe Eng. Improv. Impr. (1653) 143 A Mud, or Sludg, that lyeth frequently in deep Rivers, which is very soft. 1707 Mortimer Husb. (1721) II. 70 In that Water I put the Earth.., so as to make it a meer soft Sludge or Mud. 1745 Beverley Beck Act ii. 2 Choaked and warped up by the sludge and soil brought in by the tides. 1782 Phil. Trans. LXXII. 364 When we saw it, the moist filth, or sludge, at bottom..was two or three inches deep. 1822 Scott Nigel iii, The natural scent of the ooze and sludge left by the reflux of the tide. 1875 Smiles Boy's Voy. r. World xi. 113 A wide stretch of ground was covered by a thick deposit of sludge. 1946 L. D. Stamp Britain's Struct. & Scenery iii. 20 In tundra lands the sub-soil remains permanently frozen whilst the surface thaws in summer and, where there are steep slopes, masses of sludge slide downhill. 1959 G. H. Dury Face of Earth xv. 181 The loess records cold, very dry climate. The underlying sludge was formed in a preceding episode of moister conditions when the topsoil thawed annually. |
b. Naut. Ice imperfectly formed, or broken up into minute pieces (
cf. quots.).
| 1817 Scoresby in Ann. Reg., Chron. 534 The first appearance of ice whilst in the state of detached crystals, is called by the sailors sludge. 1820 ― Acc. Arctic Reg. I. 227 Sludge consists of a stratum of detached ice-crystals, or of snow, or of the smaller fragments of brash-ice floating on the surface of the sea. 1885 Encycl. Brit. XIX. 328 The ice first forms in thin, irregular flakes called ‘sludge’, and when this is compact enough to hold snow it is known as ‘brash’. |
c. The colour of sludge. Also
attrib.| 1962 Sunday Express 4 Feb. 19/2 Pyjama stripes—navy, ‘sludge’ or ‘smog’ on white. 1977 Vogue Feb. 90/1 From a commanding frilly and deep sludge dress, Merle Park changes into her working clothes. |
2. a. Any earthy or slimy matter or deposit; a mixture of some finely powdered substance and water.
spec. Such material formed as waste in various industrial and mechanical processes.
| 1702 Savery Miners' Friend 60 Sluge or Fine Dirt..will do my Engine no Injury. 1840 Hodgson Hist. Northumb. III. ii. 319/2 That sort of ammoniacal sleck or sludge which comes from kitchens. 1883 Haldane Workshop Rec. Ser. ii. 53/2 They [sulphites] act well with salt water, giving a soft sludge, which should be readily removed by the blow-pipe. 1920 Cross & Bevan Paper-Making 144 It constitutes a ‘sludge’, practically devoid of useful felting properties. 1933 Charlottesville (Va.) Daily Progress 22 May 6/5 The death of five men in a drainage vat at the Hess and Drucker Tannery was being investigated... The fifth was a would-be rescuer, who plunged into the tank of sludge. 1965 New Statesman 19 Nov. 809/4 (Advt.), Industrial Chemist required by Company dealing in sludges & effluents of all kinds. 1974 J. Dyson Prime Minister's Boat is Missing xxx. 180 The sludge of crude oil in the bottom of tanks. |
b. Metall. Finely crushed ore mixed with water; metalliferous slime.
| 1757 tr. Henckel's Pyritologia 341 All these cobalds or pyrites must previously be parted from the barren minerals, by stamping and washing, and made into a pure sludge. 1778 Pryce Min. Cornub. 226 Some have concluded, that Tin in the state of sludge or slime, by length of time, must grow and increase. 1839 Ure Dict. Arts 752 It is impossible to prevent some of the finely attenuated portions of the galena called sludge, floating in the water. 1898 Daily News 5 July 9/5 Further tenders have just been accepted for a quantity of sludges valued at over 1,000l. |
c. The precipitate in sewage tanks.
| 1877 J. B. Denton Sanit. Engineering 266 The third gradation of the solid matter in sewage known as ‘sludge’. 1887 Times 26 Aug. 9/4 The sediment or sludge left at the bottom of the precipitation tanks. |
d. A loose sediment that forms in boilers and other vessels in which water is habitually heated.
| 1839 R. S. Robinson Naut. Steam Eng. 123 To prevent any sludge, &c. from issuing out at the mouth of the pipe, and falling on the decks of the vessel. 1912 R. B. Dole in Rogers & Aubert Industr. Chem. iii. 47 If magnesium and sulphates are comparatively low or if suspended matter is comparatively high the scale is soft and bulky and may be in the form of sludge that can be blown or washed from the boiler. 1937 E. Pull Boiler-House Practice xv. 147 Every opportunity should be taken to remove accumulations of grease, scale, sludge and soot. 1955 Kirk & Othmer Encycl. Chem. Technol. XIV. 940 This led to the system..of maintaining at all times in the boiler water a small but sufficient excess of phosphate ion so that all calcium ion entering with the feed water would be precipitated as a loose sludge of calcium phosphate rather than as a hard scale. |
e. The mixture of water or mud fluid with cuttings that is produced in rock drilling.
| 1871 [see sludger]. 1911 Dana & Saunders Rock Drilling ii. 21 The shales will often form a sludge containing such proportions of large and small particles as to cake on the bit. 1933 R. S. Lewis Elements Mining xiv. 422 Where much sludge is made it is very important to have the water return with sufficient velocity to lift the heaviest particles in the sludge. 1963 Gloss. Mining Terms (B.S.I.) iii. 13 Sludge, rock cuttings produced by the drill bit. |
f. A dark viscous liquid or semi-solid mass deposited when a petroleum distillate is mixed with strong sulphuric acid during refining. Also called
sludge acid (see sense 4 below),
acid sludge.
| 1885 Encycl. Brit. XVIII. 719/1 The acid ‘sludge’, consisting of the oil of vitriol combined with the impurities of the oil and forming a black tarry liquid, settles to the bottom..and is drawn off. 1938 Oliver & Spangler in A. E. Dunstan et al. Sci. Petroleum IV. 2765/1 At refineries on the sea coast acid sludge was frequently discharged into the ocean. 1954 Kirk & Othmer Encycl. Chem. Technol. XIII. 493 Most refineries hydrolyze the light nonlube sludges, effecting an incomplete separation of acid tars from the weak impure acid. 1965 O. T. Fasullo Sulfuric Acid v. 127 The tendency of sludges to evolve sulfur dioxide.., in addition to the enormous quantity in which sludges are necessarily produced by the petroleum industry, makes these materials worthy subjects for the application of pollution control measures. |
g. = slime n. 4 b.
| 1900 Jrnl. Brit. Inst. Electr. Engin. XXIX. 274 In copper refining with high current densities less anode sludge is formed. 1948 T. C. Elliott Electric Accumulator Man. iii. 26 The piling up of sludge..and the creation of possible short circuits through the growths clinging to the tubes..must be avoided. 1977 Brodd & Kordesch tr. Bode's Lead-Acid Batteries iii. 222 A Pb content of more than 5% is supposed to cause difficulties during the formation of positive plates (swelling or warping or extensive sludge formation). |
h. A thick, semi-solid deposit that tends to form in oil when it is heated, exposed to the air, or mixed with another kind of oil.
| 1920 Whittaker's Electr. Engineer's Pocket-bk. (ed. 4) 245 When the transformer is examined, it is found that the windings and core are covered with a reddish-brown flocculent deposit or sludge. 1927 Jrnl. Soc. Chem. Industry 8 Apr. 135t/2 The sludge deposits which are sometimes found in hollow crankpins..are due evidently to decomposition products of the oil being thrown out by centrifugal action. 1941 D. F. Miner Insulation Electr. Apparatus iv. 81 The purification of oil used in circuit breakers and transformers consists principally in the removal of water, carbon, and sludge. 1973 G. Zwick Everyman's Guide Car Maintenance (1974) vi. 153 If the motorist has consistently been using a high grade heavy duty oil, the chances are that the interior of the engine is clean, with a bare minimum of sludge and other residues. |
i. Med. (A quantity of) sludged blood.
Cf. sludging vbl. n. 4.
| 1947 Science 7 Nov. 436/2 Many human patients have various degrees of unexplainable edema... These can now be examined for sludges. 1972 H. I. Bicher Blood Cell Aggregation ii. 27 All of this provides strong additional support for considering sludge as..a possible antecedent to thrombosis. |
3. local. (See
quot.)
| 1839 Sir G. C. Lewis Gloss. Heref., Sludge,..a wet or muddy place. |
4. attrib., as
sludge-door,
sludge-hole,
sludge-ice, etc. (see
quots.);
sludge brown,
sludge green,
sludge grey ns. and
adjs.;
sludge-coloured adj.;
sludge acid = sense 2 f above.
| 1885 American IX. 222 Around New York *sludge acid..is doing deadly work among the bivalves. 1891 Cent. Dict., Sludge acid, acid which has been used for the purification of petroleum. 1938 Oliver & Spangler in A. E. Dunstan et al. Sci. Petroleum IV. 2766/2 Formerly it was possible to use some of this weak separated sludge acid for the manufacture of superphosphate fertilizer, but the objections..to the presence of evil-smelling hydro⁓carbon derivatives in superphosphate has practically stopped this. 1965 O. T. Fasullo Sulfuric Acid v. 127 Heavy sludges are generally mixed with lighter sludge acids to produce a blend with a middle-range viscosity. |
| 1977 D. Clark Gimmel Flask v. 82, I thought this sort of *sludge brown varnish paint went out with Queen Victoria. |
| 1962 A. Lejeune Duel in Shadows vii. 91 An Englishman in a *sludge-coloured raincoat. 1979 S. Gainham in G. Hardinge Winter's Crimes XI. 69 The woman in sludge-coloured tweed. |
| 1855 Ogilvie Suppl., *Sludge-doors, in boilers, closed openings by which the matter deposited at the bottom..can be taken out. |
| 1971 Vogue 1 Oct. 127 *Sludge green knit tights. 1972 Guardian 8 Feb. 11/2 Cheesecloth smock shirt..natural, yellow, sludge green, red or blue. 1976 Times 3 Feb. 9/7 Single breasted coat..sludge green with maroon overcheck. |
| 1977 Listener 22–29 Dec. 855/4 He's a moray eel, a *sludge-grey reptilian lurker. |
| 1846 A. Young Naut. Dict. 313 There are also *sludge-holes at the ends of the water passages between the flues, by which the deposit can be raked out. |
| 1853 Kane Grinnell Exped. xxxi. (1856) 268 Suddenly a seal rose close by him in the *sludge-ice. |
| 1896 Durh. Arch. Trans. (1901) 26 A circular tank or cistern provided with an outflow or ‘*sludge’-pipe at the bottom. |
| 1887 Archit. Soc. Dict. VII. s.v., *Sludge pit, a cesspool. |
| 1883 Gresley Gloss. Coal-m. 227 *Sludge pump, a short iron pipe or tube..with which the boremeal is extracted from a borehole. |
| 1889 Pall Mall G. 31 July 6/1 It will then..be pumped through pipes extending along a jetty into the *sludge ships, for conveyance and discharge into the German Ocean. |
| 1869 Blackmore Lorna D. xliv, Here and there the ice was fibred with the trail of *sludge-weed, slanting from the side. |
Sense 4 in
Dict. becomes 5. Add:
4. fig. An amorphous or undifferentiated mass.
| 1906 Joyce Let. 3 Dec. (1966) II. 200 This he learned I suppose from the stolidly one-languaged Sludge [of teachers]. 1971 Oz No. 36. 46/3 The Underground can no longer go on evading the issue, with the aid of..the whole reactionary super-groupy sludge. 1982 Times 16 Nov. 11/1 The pungent character of each instrument is reduced to a sludge of pentatonically tinted Mantovini. |
▪ II. sludge, v. (
slʌdʒ)
[f. the n.] I. 1. trans. To convert into sludge.
| 1757 tr. Henckel's Pyritologia 42 A native metal may lie..in so light and tender a form..as that the noble metal cannot be sludged, but be carried away by the stream. 1950 Brit. Birds XLIII. 383 The bird was on a pool used for sludging boiler ash, which has been constructed within the last two years. 1978 Sci. Amer. Jan. 85 (Advt.), In industry, chromic acid and oil-water emulsions usually live only once. They do their job; then they get discharged, sludged, trucked away, and buried. |
2. To stop up, fill the crevices of (an embankment), with liquid mud.
| 1875 Knight Dict. Mech. 2217. |
3. To clear from sludge or mud.
| 1890 Eastern Morning News (Hull) 26 Sept. 1/4 For mowing the sides and bottom of Newland Beck,..also to sludge same. |
4. intr. To form or deposit sludge.
| 1941 D. F. Miner Insulation Electr. Apparatus iv. 80 Transformer oil that has begun to sludge will continue to do so after it has been purified by means of the centrifuge or filter press. 1977 Brodd & Kordesch tr. Bode's Lead-Acid Batteries iii. 271 Those plates that have been formed at 40°C with 1·06 kg/liter (acid concentration) and 74 A/m2 (current density) are the last to sludge. |
II. 5. intr. To trudge, to tramp; to labour.
Cf. slutch v. 3.
| 1908 M. & J. Findlater Crossriggs xxiii. 170 She had got to sludge back to the station in the rain, and then go home and give a cheerful account of her day. 1913 D. H. Lawrence Love Poems & Others 44 A widow o forty-five As has sludged like a horse all her life. 1954 New Statesman 3 Apr. 432/3 ‘Well, goodnight,’ he said, sludging away. |
III. 6. intr. To move slowly by solifluction.
| 1938 Geol. Mag. LXXV. 254 Only the upper 800 feet is precipitous, the lower 600 feet..consisting of vegetated scree down which recent waste is sludging. 1940 C. F. C. Hawkes Prehistoric Foundations of Europe ii. 7 Seasonal thawing will cause surface deposits to sludge over more deeply frozen subsoil: this phenomenon is called solifluxion. 1959 G. H. Dury Face of Earth xv. 177 Sludging downslope, rock-waste tends to mask the break between high and low ground. 1964 New Scientist 8 Oct. 105/2 Half frozen material sludges rapidly downhill in the spring thaw. |
Hence
sludged ppl. a.| 1941 D. F. Miner Insulation Electr. Apparatus iv. 80 No method is yet available that will..bring sludged oil back to its original condition. 1947 Science 7 Nov. 435/2 The resistance of sludged blood to its own passage through the bottlenecks of the circulatory system forcibly reduces the rates of blood flow through all the open vessels of the body. 1972 H. I. Bicher Blood Cell Aggregation ii. 35 Ischemic changes in the myocardium as a result of sludged blood. |