A Treatise on Calico Printing, Of Colour-Making, Instances of some of the foregoing Tests applied to several articles, by way of examples.

A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.


(88) This alk, has lately got much into use about Manchester, in preference to ash.

(89) Concrete ammoniac added to a solution of pure alum, the alkali and earth unite, and the clay precipitates with a small quantity of fixed air.

(90) This gave rise to the vulgar idea of iron being turned to copper, by the Anglesea copper company, as they purchase large quantities for the purpose of immersion.

* The want of requisite time among Printers and Colour-maker for such a study, his been noticed, (and just said, to be for the Inst time) but still, though the writer has great respect for some as men of good natural talents, as well as of great experience, yet he cannot but subjoin, that the neglect of such a study must certainly it a drawback on their merit, be it of what cast it may, or however they may be pressed with other immediate concerns.
Vitriolic acid containing iron, copper, or lead, a solution of mild vegetable alkali being added, it will throw down a more or less dark coloured precipitate. If the prec. be then dried and edulcorated, and pure caustic veg. alk. poured on it, if copper be in it, it will appear blue. If the prec be dried, and hepatic water added, if lead be in it, it will appear blackish. Is iron be in it, it will be found in the liquid after separation. If it contain ammoniac, by adding acid of tartar, cream of tartar will be produced. - Nitrous acid, containing vitriolic or marine acid, by adding solution of heavy earth, or sugar of lead, ponderous spar, or vitriolated lead will be produced. The marine acid is detected by solution of silver (in aqua fortis) yielding a horny precipitate. - Marine acid, containing vitriolic acid, a solution of heavy earth or sugar of lead, will produce white clouds. If it contain copper, by adding an excess of mild veg. alk. it will appear blue. If iron, it will appear blackish by saturating the acid with fixed alkali, and adding tincture of galls. - Vinegar, containing vitriolic, marine, or tartarous acid, a solution of heavy earth or sugar of lead will threw down a white insoluble prec. is marine acid, a white prec. by solution of silver. If tartarous acid, a white powder by saturating the vinegar with pot ash. If copper, a light bluish or green prec. by saturation with ammoniac. - Salt of tartar or pure veg. alk. containing any of the earths, they will be thrown down by saturating the alk. with an acid. If vitriolic acid, an insoluble prec. of a white appearance by saturating it with pure nitrous or acetous acid, and adding solution of ponderous spar, or sugar of. lead. If marine: acid, a horny substance by solution of silver. — Mineral alkali, (88) containing vitriolic or marine acid, detected as salt of tartar above. If it contain salt of tartar, it yields cream of tartar by adding acid of tartar. - Caustic spirit of ammoniac, or vol. alk. containing fixed, air, yields a chalky substance by adding solution of lime in marine acid. - Concrete ammoniac, containing salt of tartar or sal ammoniac, by heating it on an iron instrument, a digestive salt will Be left behind; but if it be pure it will entirely volatilize. Spirit of wine being offered to it crystal's will be thrown down. - Spirit of hartshorn containing lime, effervesces by adding an acid;, or it yields no crystals on spirit of wine being added; Sal ammoniac is pure, will entirely volatilize by heat; if not, it will form a prec. By adding solution of silver or sugar of lead. — Nitre, containing marine acid, the marine acid is detected by solution of silver, shewing a horny prec. — Glauber's salt, by an insoluble prec. or heavy spar, by adding solution of heavy earth; impure nitre is likewise detected by its bitter taste and weak detonation. - Alum (which should be mere earth of alum, vitriolic acid and water,) (89) containing iron, the lixivium of Prussian blue produces a blue; tincture of galls a black: If it contain copper, an alkali tinges the liquor blue. - Corrosive sublimate containing arsenic mild vol. alk. will precipitate it, and if the liquor be filtered, and cuprum ammoniacum added, a transparent blue liquor will be formed, and the pure corrosive sublimate left free; but if it contain arsenic, the prec. will be green. — Cream of tartar containing vitriolic salts, yields a white prec. insoluble in nitrous acid, by adding sugar of lead. If it contain copper, it is detected by vol. alk. held over the fumes. If genuine it is known by its peculiar smell. - Sugar of Lead containing nitre, gives the smell of aqua fortis, by warming the solution, and adding vitriolic acid.- Roman vitriol, if pure, by adding caustic vol. alk. to the solution, will at first appear turbid; but more of the alk. will render it transparent. If it contain iron a black calx will be thrown down; if it contain zink, it will be white. Green Copperas containing copper, a piece of polished iron being put into a solution of it, it will be covered with a coat of copper.(90) - White copperas, or vitriol of zinc containing copper, is detected by vol. alk. held over the fumes. If iron, it is detected by tincture of galls. - Tin having lead combined with it, or pouring strong aqua fortis on it and setting it in a warm place, the tin will be calcined while the lead will remain free. Vol. alk, liver of sulphur, hepatic water, and sugar of lead, will detect arsenic, if any be in it besides the lead, by shewing a yellowish green precipitate, by first adding an alkaline felt, and then adding cuprum ammoniacum to the filtered liquid. Verdigrease containing lime, a selenite will be formed by offering diluted vitriolic acid to it Gypsum, i. e. vitriolic acid combined with lime, may be detected the same way. Iron containing copper, is shewn by a blue appearance, on digesting the iron with caustic vol. alk. or isa small quantity of the filings be dissolved in marine acid, and a polished plate of iron be added, it will be coated with copper.

N.B. the Writer has said (note 85) tests may be had at several Chymisls, but it is here added C. O'Brien will give any one, who is known by him, as ofcongenial wishes with himself, particular and useful intimation respecting them, by applying to him personally, or at his house Islington, his views being (as several times said) to advance the respectability as the business beyond every other concern,(ke Prel. Sug. General Reflections, and elsewhere.)

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