Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 310

For use, one of these discs is to be broken into pieces, laid in tepid water, and set in a warm place during 12 hours, when the soft ma.s.s will serve the purpose of beer yeast.

_b._ (PATENT YEAST.) Take of hops, 6 oz.; water, 3 galls.; simmer for 3 hours, strain, and in 10 minutes stir in of ground malt, 1/2 peck; next reboil the hops in water, as before, and let the strained liquor run into the first mash, which must then be well stirred up, covered over, and left for 4 hours; after that time drain off the wort, and, when the temperature has fallen to 90 Fahr., set it to work with yeast (preferably patent), 1 pint; after standing for 20 to 24 hours in a warm place, take off the sc.u.m, strain it through a coa.r.s.e hair sieve, and it will be fit for use. 1 pint is said to be enough for 1 bushel of bread.

_Obs._ The preparation of artificial yeast, and subst.i.tutes for yeast, has long engaged the attention of both the scientific chemist and the practical tradesman. The subject is, undoubtedly, of great importance to emigrants and voyagers. The above processes, by good management, yield products which are all that can be desired.

=YEL'LOW DYES.= The following substances impart a yellow to goods, either at once or after they have been mordanted with alumina or tin:--annotta, barberry root, dyer's broom, French berries, fustic, fustet, quercitron bark, and turmeric. Goods mordanted with acetate of lead, and afterwards pa.s.sed through a bath of chromate of potash, acquire a brilliant chrome-yellow colour;--solution of sulphate or acetate of iron, followed by immersion in potash or lime water, gives a buff or orange;--orpiment, dissolved in ammonia water, imparts a golden yellow. (See the above-named substances, in their alphabetical places.) An aniline yellow (chrysaniline) has recently been obtained by Mr Nicholson, which is said to be a most valuable dye-stuff, comparable, indeed, with the aniline reds and purples.

=YELLOW FE"VER.= The bilious remittent fever of hot climates. It is very common in the West Indies and the Southern States of America. New Orleans has been several times nearly depopulated by it.

=YELLOW PIG'MENTS.= Of these the princ.i.p.al are--

=Brown Pink.= _Prep._ Take of French berries and pearlash, of each 1 lb.; fustic chips, 1/2 lb.; water, 2 galls.; boil in a tin or pewter vessel, and strain the decoction through flannel whilst hot; then dissolve alum, 1-1/2 lb. in hot water, 2-1/2 galls.; add the solution to the strained decoction as long as a precipitate falls, which must afterwards be washed, drained, and dried. Some manufacturers omit the fustic. A good glazing colour, when ground in linseed, and used with drying oil.

=Yellow, Chrome.= _Syn._ CHROMATE OF LEAD, YELLOW C. OF L.; PLUMBI CHROMAS, PLUMBI CHROMAS FLAVUM, L. The preparation of the pure salt is noticed under CHROMIUM and LEAD; that of the commercial pigment is as follows:

1. Add a filtered solution of nitrate or acetate of lead to a like solution of neutral chromate of potash as long as a precipitate falls; then collect this, wash it well with clean soft water, and dry it out of the reach of sulphuretted vapours.

2. To the lye of chromate of potash, prepared by roasting the chrome ore with nitre, and lixiviation with water, add a solution of acetate of lead, and otherwise proceed as before.

3. Dissolve acetate of lead in warm water, and add of sulphuric acid, q. s. to convert it into sulphate of lead; decant the clear liquid (vinegar), wash the residuum with soft water, and digest it, with agitation, in a hot solution of neutral (yellow) chromate of potash, containing 1 part of that salt to every three parts of sulphate of lead operated on; afterwards decant the liquid, which is a solution of sulphate of potash, and carefully drain, wash, and dry the newly formed pigment.

The product contains much sulphate of lead, but covers as well, and has as good a colour, as pure chromate of lead, whilst it is much cheaper. The shade may be varied by increasing or lessening the quant.i.ty of the chromate.[273]

[Footnote 273: Armengaud's 'Genie Industriel,' April, 1853.]

_Obs._ Four shades of this beautiful pigment are met with in the shops, viz. pale yellow or straw colour, yellow, deep yellow, and orange. The former are made by adding a little alum or sulphuric acid to the solution of the chromate before mixing it with the solution of lead; the last, by the addition of a little subacetate of lead (tribasic acetate), or by was.h.i.+ng the precipitate with a weak alkaline lye. The darker colour appears to arise from a little 'dichromate' being thrown down intimately mixed with the neutral chromate, and the paler shades from a slight excess of acid, or from the presence of water-sulphate of lead, and, occasionally, alumina. The colour is also influenced by the temperature of the solutions at the time of admixture. Anthon has found that, when hot solutions of equal equivalents of acetate of lead (190 parts) and chromate of potash (100 parts, both neutral and in crystals) are mixed, the yellow precipitate, when dried, is anhydrous; but when the mixture is made at ordinary temperatures, the precipitate has a paler yellow, and when dried contains 1 eq., or nearly 5-1/4% of water. ('Buch. Rept.') It thus appears that the shades of colour of chrome yellow may be varied, without any foreign addition. In practice, the third formula will be found very satisfactory. See ORANGE CHROME and CHROME RED.

=Dutch Pink.= _Prep._ Take of French berries, 1 lb.; turmeric, 1/2 lb.; alum, 1/2 lb.; water, 1-1/2 gall.; boil 1/2 an hour, strain, evaporate to 2 quarts, adding of whiting, 3 lbs., and dry by a gentle heat. Starch, or white lead, is sometimes employed instead of whiting, to give it a body.

Golden yellow. Used as a pigment; but will not glaze like brown pink.

=English Pink.= _Syn._ LIGHT PINK. As the last, but using 5 lbs. of whiting.

=Indian Yellow.= See PURREE.

=King's Yellow.= Fact.i.tious tersulphuret of a.r.s.enic.

=Naples Yellow.= _Syn._ MINERAL YELLOW. _Prep._ 1. Take of metallic antimony, in powder, 3 lbs.; red lead, 2 lbs.; oxide of zinc, 1 lb.; mix, calcine, well triturate the calx, and fuse it in a covered crucible; the fused ma.s.s must be reduced to an impalpable powder by grinding and elutriation.

2. Flake white, 1-1/2 lb.; diaph.o.r.etic antimony, 1/4 lb.; calcined alum, 1 oz.; sal ammoniac, 2 oz.; calcine in a covered crucible with a moderate heat for 3 hours, so that at the end it may be barely red hot. More antimony and sal ammoniac turn it on the gold colour.

3. (Guimel.) Washed diaph.o.r.etic antimony, 1 part; pure red lead, 2 parts; grind them to a paste with water, and expose this mixture to a moderate red heat for 4 or 5 hours, as before. Used in oil, porcelain, and enamel painting. Chrome has now nearly superseded it for ordinary purposes.

=Patent Yellow.= _Syn._ Ca.s.sEL YELLOW, MONTPELLIER Y., TURNER'S Y. _Prep._ Take of dry chloride of lead, 28 parts; pure carbonate of lead, 27 parts; grind them together, fuse, and powder.

2. Common salt, 1 part, and litharge, 4 parts, are ground together with water, and digested at a gentle heat for some time, water being added to supply the loss by evaporation; the carbonate of soda formed is then washed out with more water, and the white residuum heated until it acquires a fine yellow colour. Works well in oil. Chiefly used in coach-painting. See OXYCHLORIDE OF LEAD.

=Weld Yellow.= Prepared from a decoction of weld brightened with a little alum, in the same manner as Dutch pink. Used chiefly for paper hangings.

=YTTRIUM. Y.= The oxide of this metal (yttria), a rare, white earth, was discovered by Gadolin, in 1794, in a mineral from Ytterby, in Sweden, since called gadolinite. Yttrium was obtained by Wohler in 1828, as a brittle, dark-grey metal, made from the chloride by the action of sodium.

Its salts have in general a sweetish taste, and the sulphate and several others an amethystine colour. Its solutions are precipitated by pure alkalies, but alkaline carbonates, especially carbonate of ammonium, dissolve it in the cold. They are distinguished from glucinium salts by the colour of the sulphate by being insoluble in pure alkalies, and by yielding a white precipitate with ferrocyanide of pota.s.sium. Yttria may be obtained from gadolinite by a similar process to that by which glucina is extracted from the beryl.

According to Professor Mosander, ordinary yttria is a mixture of the oxides of not less than three metals--yttrium, erbium, and terbium. These metals differ from each other in many important particulars. The first is a powerful base, and the others are said to be weak ones. They are separated with extreme difficulty, and are only interesting in a scientific point of view.

=ZAF'FRE.= _Syn._ SAFFRA, SAFFLOR, ZAFFER. Crude oxide of cobalt, obtained by roasting cobalt ore, reduced to an impalpable powder, and then ground with 2 or 3 parts of very pure quartzose or siliceous sand. Used as a blue colour by enamellers and painters on porcelain and gla.s.s. Chiefly imported from Saxony. See SMALTS.

=ZE"RO.= See THERMOMETER.

=ZESTS.= See POWDERS, SAUCE, SPICE, &c.

=ZINC.= Zn. _Syn._ ZINK, SPELTER; ZINc.u.m. (Ph. L., E., & D.), L. This metal was first noticed by Paracelsus, in the 16th century, who called it 'zinetum,' but its ores must have been known at a much earlier period, as the ancients were acquainted with the manufacture of bra.s.s.

_Prep._ The zinc of commerce is obtained from the native sulphide (zinc blende), or carbonate (calamine), by roasting those ores, and distilling the calx with carbonaceous matter in a covered earthen crucible, having its bottom connected with an iron tube, which terminates over a vessel of water situated beneath the furnace. The first portion that pa.s.ses over contains cadmium and a.r.s.enic, and is indicated by what is technically called 'brown blaze,' but when the metallic vapour begins to burn with a bluish-white flame, or the 'blue blaze' commences, the volatilised metal is collected.

The following method, by which several pounds of chemically pure zinc may be obtained in about 1/4 of an hour, will be found very useful:--Melt the zinc of commerce in a common crucible, and granulate it by throwing it into a tolerably deep vessel of water, taking care that the metal be very hot at the time; dry the metallic grains, and dispose them by layers in a Hessian crucible with 1/4 of their weight of nitrate of pota.s.sium, using the precaution to place a slight excess at the top and at the bottom; cover the crucible, and secure the lid, then apply heat; after the vivid deflagration which occurs is over, remove the crucible from the fire, separate the dross with a tube, and, lastly, run the zinc into an ingot mould. This zinc, tested in Marsh's apparatus during entire days, has never given any stain, and in solution the most sensitive reagents, such as hydro-sulphocyanic acid, have never indicated the least atom of iron.

('Journ. de Pharm.')

_Prop._ Zinc is a bluish-white metal, having the sp. gr. 68 to 72; tough (under some circ.u.mstances, brittle) when cold, ductile and malleable at from 250 to 300 Fahr.; brittle and easily pulverised at 400; fuses at 773 (Daniell); at a white heat it boils, and sublimes unchanged in close vessels; heated to whiteness (941 Daniell) in contact with the air, it burns with a brilliant green light, and is converted into oxide. It is very soluble in dilute sulphuric and hydrochloric acid, with the evolution of hydrogen gas. It is little acted on by the air, even when moist. The salts of zinc are colourless.

_Pur._ Commercial zinc is never pure. Its specific gravity is 686. It is soluble in nitric, hydrochloric, and dilute sulphuric acids.

_Tests._ 1. The solutions of zinc give a gelatinous white precipitate with the alkalies and carbonate of ammonium, which is completely redissolved by an excess of the precipitant.--2. The carbonates of pota.s.sium and sodium give a white precipitate of carbonate of zinc. All the above precipitates acquire a lemon-yellow colour when dried and heated, but again become white on cooling.--3. Sulphide of ammonium gives, in neutral solutions, a white precipitate, insoluble in excess of the precipitant, or in solutions of hydrate of pota.s.sium or ammonium, but freely soluble in the dilute mineral acids.--4. Sulphuretted hydrogen, in neutral and alkaline solutions, also gives a like white precipitate.--5. Ferrocyanide of pota.s.sium gives a gelatinous white precipitate.

_Estim., &c._--_a._ 100 gr. are digested in dilute hydrochloric acid in excess, and the insoluble portion, which is chiefly carbon, dried and weighed.

_b._ The acidulous solution (see _a_) is next treated with a current of sulphuretted hydrogen until it smells very strongly of that gas; the whole is then left for some time in a warm situation. The precipitate which subsides consists of the sulphides of a.r.s.enic, cadmium, copper, lead, &c., if any of these metals were present in the sample.

_c._ The filtrate from _b_, after being boiled, is treated with a little nitric acid, after which it is again boiled, and, when cold, is precipitated with carbonate of barium added in excess; the precipitate (ferric hydrate) is then collected, dried, ignited, and weighed. The weight, in grains, multiplied by 7, gives the percentage of iron in the sample examined.

_d_. The filtrate from _c_ is next precipitated with dilute sulphuric acid, and solution of carbonate of sodium is added in excess to the filtered liquid; the whole is then boiled, after which the new precipitate is washed, dried, gently ignited for some time, and then cooled and weighed. The weight, in grains, multiplied by 80247, gives the percentage of pure zinc in the sample.

_Uses, &c._--Zinc is used to form galvanic plates; in fireworks, and in medicine. Of late years it has also been extensively used in the manufacture of vessels of capacity, tubing, sheets for roofing, and other things that require lightness and durability.

=Zinc, Amalgamated=, which is employed for voltaic batteries, is prepared as follows:--The plates, having been scoured with emery, are immersed for a few seconds in dilute sulphuric acid, then rinsed in clean soft water, and, after the loose water has drained from their surface, dipped into a strong solution of either mercuric nitrate or chloride, or into equal parts of a mixture of saturated solutions of mercuric chloride and acetate of lead; the plates are, lastly, dipped into water, and then rubbed with a soft cloth. Another and simpler method is to rub mercury over the plates while wet with dilute sulphuric acid.

=Zinc, Granulated.= _Syn._ ZINc.u.m GRANULATUM (B. P.). Fuse commercial zinc in a crucible, pour it in a very thin stream into a bucket of cold water, and afterwards dry the zinc.

=Zinc, Ac'etate of.= Zn(C_{2}H_{3}O_{2})_{2}. _Syn._ ZINCI ACETAS, L.

_Prep._ 1. (Ph. D.) Acetate of lead, 1 lb., is dissolved in distilled water, 2-1/2 pints, and the solution being placed in a cylindrical jar, sheet zinc, 4 oz., rolled into a coil, is immersed therein; after 24 hours the liquid is decanted, evaporated to 15 oz., and solution of hypochlorite of calcium added drop by drop, until a reddish precipitate ceases to form; the liquid is then filtered, acidulated by the addition of a few drops of acetic acid, reduced by evaporation to 10 fl. oz., and set aside to crystallise; the crystals are dried on bibulous paper set on a porous brick, and then preserved in a well-stopped bottle. More crystals may be obtained from the mother-liquor.

2. (B. P.) Add 2 oz. of carbonate of zinc in successive portions to 3 fl.

oz. of acetic acid, previously mixed with 6 fl. oz. of distilled water, in a flask; heat gently, add by degrees 2 fl. oz. of acid, or q. s., till the carbonate is dissolved; boil for a few minutes, filter while hot, and set it aside for two days to crystallise. Decant the mother liquor, evaporate to one half, and again set it aside for two days to crystallise. Place the crystals in a funnel to drain, then spread them on filtering paper on a porous tile; and dry them by exposure to the air at ordinary temperatures.

_Prop., &c._ Efflorescent, white, hexagonal plates, having a powerful styptic taste; very soluble in water; less soluble in alcohol; decomposed by heat. It is tonic, antispasmodic, and emetic.--_Dose_, 1 to 2 gr.; as an emetic, 10 to 20 gr.; externally, 2 or 3 gr. to water, 1 fl. oz., as an astringent lotion or injection.

=Zinc, Bro'mide of.= ZnBr_{2}. _Syn._ ZINCI BROMIDUM, L. Prepared like the corresponding salt of iron.

=Zinc, Car'bonate of.= ZnCO_{3}. _Syn._ ZINCI CARBONAS PURUM, ZINCI CARBONAS (B. P., Ph. D.), L. _Prep._ 1. (Ph. D.) Solution of chloride of zinc (Ph. D.), 1 pint is added, in successive portions, to a solution of crystallised carbonate of sodium of commerce, 2 lbs., dissolved in boiling distilled water, 6 pints, and the whole is boiled until gas ceases to be evolved; the precipitate is then washed, and dried, at first on blotting-paper, and, finally, by a steam or water heat.

2. (B. P.) Dissolve 10-1/2 oz. carbonate of soda with 1 pint of boiling water in a capacious porcelain vessel, and pour into it 10 oz. of sulphate of zinc, also dissolved in 1 pint of water, stirring diligently. Boil for 15 minutes after effervescence has ceased, and let the precipitate subside. Decant the supernatant liquor, pour on the precipitate 3 pints of boiling distilled water, agitating briskly; let the precipitate again subside, and repeat the process of affusion of hot distilled water and subsidence till the was.h.i.+ngs are no longer precipitated by chloride of barium. Collect the precipitate on calico, let it drain, and dry it with a gentle heat.