Cooley's Cyclopaedia of Practical Receipts Volume I Part 270

=GREEN.= _Syn._ VIRIDIS, L.; VERT, Fr. Of the colour of the leaves of growing plants; _subst._ a green colour.

=GREEN DYE.= _Syn._ TEINTE VERTE, Fr. All the green dyes in use, with the practically unimportant exception of Chinese green and oxide of chromium green, are compounded of blue and yellow. The goods, in practice, are generally dyed blue first, observing to regulate the shade according to that of the intended green; they are then dried, rinsed, and pa.s.sed through a yellow bath, with the like precautions, until the proper shade is obtained. See BLUE DYE, YELLOW DYE, &c.

=GREEN PIG'MENTS.= Several of the green pigments of commerce are obtained from copper. Oxide of chromium furnishes some which are very beautiful.

Many are formed by the mere mechanical admixture of blue and yellow pigments. The bright blues and yellows, when mixed in this way, produce the liveliest greens; orange, or red and blue, and the yellowish browns and blue, the more dingy greens. In this way are produced all the extemporaneous greens of the artist. Nickel and t.i.tanium also furnish green colours, but these are not in common use. The following list embraces all the best-known and most useful green pigments:--

=Green a.r.s.en'ical.= a.r.s.enite and aceto-a.r.s.enite of copper. See GREEN, SCHEELE'S and SCHWEINFURT (_below_).

=Green, Barth's.= From yellow lake, Prussian blue, and clay, ground together.

=Green, Bice.= Same as mountain green.

=Green, Bremen.= This is properly green verditer, but other preparations are frequently sold under the name.

=Green, Brighton.= A mixture of impure acetate of copper and chalk, prepared as follows:--

To sulphate of copper, 7 lbs., add sugar of lead, 3 lbs.; each separately dissolved in water, 5 pints; mix the solutions, stir in of whiting, 24 lbs., set the resulting paste on chalk stones, and when dry grind it to powder.

=Green, Brunswick.= This is probably a crude chloride of copper, but a mixture of carbonate of copper and alumina or chalk is now commonly sold under the name in the shops.

_Prep._ 1. A saturated solution of sal ammoniac, 3 parts, is poured over copper filings or shreds, 2 parts, contained in a vessel capable of being closed up, and the mixture is kept in a warm place for some weeks, when the newly formed green pigment is separated from the unoxidised copper, by was.h.i.+ng the mixture on a sieve; it is then edulcorated with water, and slowly dried in the shade. Colour very deep and rich. The lighter shades are produced by the addition of sulphate of baryta.

2. A solution of crude carbonate of ammonia or bone spirit is added to a mixed solution of alum and blue vitriol, as long as it affects the liquor; in a short time the precipitate is collected, washed and dried. The various shades of green are produced by using different quant.i.ties of alum, which pales and cheapens it.

=Green, Chrome.= The superb green pigment used by enamellers under this name is the green oxide or sesquioxide of chromium. A hydrated oxide of chromium forms the emerald green of Pannetier; it is prepared by melting in a crucible equivalent quant.i.ties of anhydrous boracic acid and b.i.+.c.hromate of pota.s.sium, and treating the fused ma.s.s with water. The hydrated oxide thus produced is washed and finely triturated.

The chrome green of the oil and colour shops is a mixture of chrome yellow and Prussian green.

=Green, Cop'per.= Green bice or mountain green, Brunswick green, emerald green, verditer, and several other well-known pigments, may be thus named.

=Green, Em'erald.= This term is commonly applied to the aceto-a.r.s.enite of copper, as prepared in England. It is the same compound, chemically speaking, as Schweinfurt green (which _see_).

_Prep._ A pulp is formed with verdigris, 1 part, and boiling water q. s., and after being pa.s.sed through a sieve, to remove lumps, is added gradually to a boiling solution of a.r.s.enious acid, 1 part, in water, 10 parts, the mixture being constantly stirred until the precipitate becomes a heavy, granular powder, when it is collected on a calico filter, and dried on chalk stones.

=Green, Frise.= _Syn._ FRIEZLAND GREEN. This resembles Brunswick green.

=Green, Gellart's.= A mixture of cobalt blue and flowers of zinc with some yellow pigment.

=Green, Impe'rial.= Schweinfurt green (see _below_).

=Green, Iris.= A pigment prepared by grinding the juice of the petals of the blue flag with quicklime. It is very fugitive.

=Green Lake.= See LAKE.

=Green, Min'eral.= This is the same as mountain green.

=Green, Mitis.= Another of the many synonyms of Schweinfurt green.

=Green, Mountain.= This pigment is properly the native green carbonate or bicarbonate of copper (malachite) ground to powder, either with or without the addition of a little orpiment or chrome yellow. That of the shops is commonly prepared by adding a solution of carbonate of soda, or of pota.s.sa, to a hot mixed solution of sulphate of copper and alum. Green verditer is commonly sold for this article. According to Watts, mountain green is the same as Neuwieder green.

=Green, Neuwieder.= Schweinfurt green mixed with gypsum or sulphate of baryta.

=Green, Prussian.= The sediment of the process of making Prussian blue from bullock's blood or horns, before it has had the hydrochloric acid added to it. It is also prepared by pouring liquid chloride upon freshly precipitated Prussian blue. As now sold, this pigment is generally a mixture of Prussian blue and gamboge.

=Green, Rinman's.= This resembles that of Gellert.

=Green, Sap.= A very fugitive pigment, prepared from the juice of buckthorn berries. The berries are allowed to ferment for a week or eight days in a wooden tub. The juice is then pressed out, strained, a little alum added, and the whole evaporated to a proper consistence; it is next run into pigs' bladders, and hung up in a dry situation to harden. An inferior article is made from the juice of black alder, and of evergreen privet. It is a common practice to add 3/4 pint of lime water and 1/2 oz.

of gum Arabic to every pint of either of the above juices.

=Green, Scheele's.= This is a.r.s.enite of copper.

_Prep._ 1. White a.r.s.enic (in powder), 1 part; commercial potash, 2 parts; boiling water, 35 parts; dissolve, filter, and add the solution gradually, whilst still warm, to a filtered solution of sulphate of copper (cryst.), 2 parts, as long as a precipitate falls; lastly, wash the newly formed pigment with warm water, and dry it.

2. (Ure.) Powdered a.r.s.enious acid, 11 oz.; carbonate of pota.s.sa, 1-1/2 lb.; boiling water, 1 gall.; dissolve, filter, and add the solution, as before, to another solution of crystallised sulphate of copper, 2 lbs., in water, 3 galls. _Prod._ 1-1/2 lb. A very fine gra.s.s-green colour.

=Green, Schweinfurt.= This splendid green pigment is the aceto-a.r.s.enite of copper.

_Prep._ 1. Acetate of copper and a.r.s.enious acid, equal parts, are each dissolved separately in the least possible quant.i.ty of boiling water, and the solutions mixed whilst still as hot as possible; an olive-green precipitate falls, which, by being boiled in the liquor 5 or 6 minutes, changes to a dense granular powder of a superb green colour.

2. Instead of boiling the solution containing the precipitate, it is allowed to cool and stand for several hours, or until the powder a.s.sumes a granular and beautiful tint. Very rich.

3. (Kastner.) a.r.s.enious acid, 8 lbs., is dissolved in water as before, and added to verdigris, 9 or 10 lbs., diffused through water q. s., at 120 Fahr., the pap of the other being first pa.s.sed through a sieve; the mixed ingredients are then set aside till the mutual reaction produces the proper shade.

4. (Dr Ure.) Sulphate of copper, 50 lbs., and lime, 10 lbs., are dissolved in good vinegar, 20 galls., and a boiling hot solution of white a.r.s.enic, 50 lbs., is conveyed as quickly as possible into the liquor; the mixture is stirred several times, and then allowed to subside, after which it is collected on a filter, dried and powdered. The supernatant liquor is employed the next time for dissolving the a.r.s.enic.

5. See GREEN, EMERALD (_above_).

_Obs._ This is a very fine, permanent green pigment. "A great deal of needless alarm has been excited about its supposed deleterious effects. It is extensively employed for staining wall-papers, and persons inhabiting rooms thus papered are said to have had their health seriously deranged by the a.r.s.enical fumes evolved from it. Now, it is utterly impossible that a.r.s.enic could volatilise from such a compound at ordinary temperatures; it does not decompose at any temperature below redness." (Watts.) [It is, however, probable that the air of such apartments is sometimes charged with the poisonous pigment through its becoming mechanically detached from the paper. To breathe an atmosphere so impregnated would be dangerous. The use of papers coloured with Scheele's green, especially of the kind called 'flock,' should, therefore, be carefully avoided.--ED.]

=Verd'igris.= See COPPER (Acetates) and VERDIGRIS.

=Green, Verd'iter.= This is essentially a mixture of oxide and carbonate of copper in uncertain proportions, with chalk. Fact.i.tious green bice and mountain green have a like composition. See VERDITER.

=Green, Verona.= The mineral called green earth.

=Green, Vienna.= The same as Schweinfurt green.

=GREEN SICKNESS.= See CHLOROSIS.

=GREEK FIRE.= This compound, so much used in ancient warfare, is believed to have had naphtha for its chief ingredient. According to some authorities, it was a mixture of asphalt, nitre, and sulphur.

=GREGORY'S SALT.= The crude hydrochlorate of morphia, prepared by Gregory's process. It is a double hydrochlorate of morphia and codeia.

=GRINDELIA ROBUSTA.= A perennial plant belonging to the natural order _Compositae_; a native of California, in which state it is largely used against poisoning by the "poison oak" (the _Rhus toxicodendron_). Of late years it is said to have been in American medical practice used with excellent effect in asthma and kindred diseases. Dr Q. C. Smith, writing to the 'Pacific Medical and Surgical Journal' for April, 1875, states one patient to whom pills made of the solid extract were administered, had suffered from severe and frequent attacks of asthma since childhood, and had found no relief from various remedies. Dr Smith gave his patient the extract of the grindelia in pills of three grains each, one three times a day for two or three days, then a pill at bedtime only, for eight or ten days longer. Under this mode of treatment the attacks are said to have been much less severe, and less frequent; the patient not only gaining in strength and general health in the meantime, but having experienced an immunity from attack for four months. The parts of the plant used are the selected leaves and tops.

=GRIND'ING.= The operation of reducing substances to powder by attrition or friction. In the laboratory, the term is chiefly applied to powdering by means of a mill or by mechanical power, in opposition to simple pounding or trituration in a mortar or with a slab and muller. All the princ.i.p.al powders, paints, &c., sold by the druggist, drysalter, and colourman, are reduced in the drug or colour mill. Recently machinery has even been applied to the common mortar. An ingenious and very useful contrivance of this kind is the 'mechanical mortar' of Mr H. Goodhall, of Derby.

=GRIND'STONES. (Artificial).= Washed siliceous sand, 3 or 4 parts; sh.e.l.l-lac, 1 part; melt together, and form the ma.s.s into the proper shape whilst warm, with strong pressure. The fineness of the sand must depend on the work the stone is intended for. The same composition is formed upon pieces of wood, as corn rubbers, and for the purpose of sharpening knives, and cutting stones, sh.e.l.ls, &c. See EMERY.