What is "blue vitriol"

Vitriol \Vit"ri*ol\, n. [F. vitriol; cf. Pr. vitriol, vetriol, Sp. & Pg. vitriolo, It. vitriuolo; fr. L. vitreolus of glass, vitreus vitreous. See Vitreous.] (Chem.)

1. A sulphate of any one of certain metals, as copper, iron, zinc, cobalt. So called on account of the glassy appearance or luster.

2. Sulphuric acid; -- called also oil of vitriol. So called because first made by the distillation of green vitriol. See Sulphuric acid, under Sulphuric.

   Blue vitriol. See under Blue.

   Green vitriol, ferrous sulphate; copperas. See under Green.

   Oil of vitriol, sulphuric or vitriolic acid; -- popularly so called because it has the consistency of oil.

   Red vitriol, a native sulphate of cobalt.

   Vitriol of Mars, ferric sulphate, a white crystalline substance which dissolves in water, forming a red solution.

   White vitriol, zinc sulphate, a white crystalline substance used in medicine and in dyeing. It is usually obtained by dissolving zinc in sulphuric acid, or by roasting and oxidizing certain zinc ores. Formerly called also vitriol of zinc.

Blue \Blue\ (bl[=u]), a. [Compar. Bluer (bl[=u]"[~e]r); superl. Bluest.] [OE. bla, blo, blew, blue, livid, black, fr. Icel.bl[=a]r livid; akin to Dan. blaa blue, Sw. bl[*a], D. blauw, OHG. bl[=a]o, G. blau; but influenced in form by F. bleu, from OHG. bl[=a]o.]

1. Having the color of the clear sky, or a hue resembling it, whether lighter or darker; as, the deep, blue sea; as blue as a sapphire; blue violets. ``The blue firmament.''
   --Milton.

2. Pale, without redness or glare, -- said of a flame; hence, of the color of burning brimstone, betokening the presence of ghosts or devils; as, the candle burns blue; the air was blue with oaths.

3. Low in spirits; melancholy; as, to feel blue.

4. Suited to produce low spirits; gloomy in prospect; as, thongs looked blue. [Colloq.]

5. Severe or over strict in morals; gloom; as, blue and sour religionists; suiting one who is over strict in morals; inculcating an impracticable, severe, or gloomy mortality; as, blue laws.

6. Literary; -- applied to women; -- an abbreviation of bluestocking. [Colloq.] The ladies were very blue and well informed. --Thackeray. Blue asbestus. See Crocidolite. Blue black, of, or having, a very dark blue color, almost black. Blue blood. See under Blood. Blue buck (Zo["o]l.), a small South African antelope ( Cephalophus pygm[ae]us); also applied to a larger species ( [AE]goceras leucoph[ae]us); the blaubok. Blue cod (Zo["o]l.), the buffalo cod. Blue crab (Zo["o]l.), the common edible crab of the Atlantic coast of the United States ( Callinectes hastatus). Blue curls (Bot.), a common plant ( Trichostema dichotomum), resembling pennyroyal, and hence called also bastard pennyroyal. Blue devils, apparitions supposed to be seen by persons suffering with delirium tremens; hence, very low spirits. ``Can Gumbo shut the hall door upon blue devils, or lay them all in a red sea of claret?'' --Thackeray. Blue gage. See under Gage, a plum. Blue gum, an Australian myrtaceous tree ( Eucalyptus globulus), of the loftiest proportions, now cultivated in tropical and warm temperate regions for its timber, and as a protection against malaria. The essential oil is beginning to be used in medicine. The timber is very useful. See Eucalyptus. Blue jack, Blue stone, blue vitriol; sulphate of copper. Blue jacket, a man-of war's man; a sailor wearing a naval uniform. Blue jaundice. See under Jaundice. Blue laws, a name first used in the eighteenth century to describe certain supposititious laws of extreme rigor reported to have been enacted in New Haven; hence, any puritanical laws. [U. S.] Blue light, a composition which burns with a brilliant blue flame; -- used in pyrotechnics and as a night signal at sea, and in military operations. Blue mantle (Her.), one of the four pursuivants of the English college of arms; -- so called from the color of his official robes. Blue mass, a preparation of mercury from which is formed the blue pill. --McElrath. Blue mold or Blue mould, the blue fungus ( Aspergillus glaucus) which grows on cheese. --Brande & C. Blue Monday,

   1. a Monday following a Sunday of dissipation, or itself given to dissipation (as the Monday before Lent).

   2. a Monday considered as depressing because it is a workday in contrast to the relaxation of the weekend. Blue ointment (Med.), mercurial ointment. Blue Peter (British Marine), a blue flag with a white square in the center, used as a signal for sailing, to recall boats, etc. It is a corruption of blue repeater, one of the British signal flags. Blue pill. (Med.)

      1. A pill of prepared mercury, used as an aperient, etc.

      2. Blue mass. Blue ribbon.

         1. The ribbon worn by members of the order of the Garter; -- hence, a member of that order.

         2. Anything the attainment of which is an object of great ambition; a distinction; a prize. ``These [scholarships] were the
            --blue ribbon of the college.''
            --Farrar.

   3. The distinctive badge of certain temperance or total abstinence organizations, as of the
      --Blue ribbon Army.

      Blue ruin, utter ruin; also, gin. [Eng. Slang]
      --Carlyle.

      Blue spar (Min.), azure spar; lazulite. See Lazulite.

      Blue thrush (Zo["o]l.), a European and Asiatic thrush ( Petrocossyphus cyaneas).

      Blue verditer. See Verditer.

      Blue vitriol (Chem.), sulphate of copper, a violet blue crystallized salt, used in electric batteries, calico printing, etc.

      Blue water, the open ocean.

      Big Blue, the International Business Machines corporation. [Wall Street slang.] PJC

      To look blue, to look disheartened or dejected.

      True blue, genuine and thorough; not modified, nor mixed; not spurious; specifically, of uncompromising Presbyterianism, blue being the color adopted by the Covenanters.

      For his religion . . . 'T was Presbyterian, true blue.
      --Hudibras.

n. (context obsolete chemistry English) copper sulfate

n. hydrated blue crystalline form of copper sulfate [syn: blue copperas, blue stone, chalcanthite]