Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 311

=Zinc, Chlo"ride of.= ZnCl_{2}. _Syn._ b.u.t.tER OF ZINC, MURIATE OF Z.; ZINCI CHLORIDUM (B. P., Ph. L.), Z. MURIAS, L. _Prep._ 1. By heating metallic zinc in chlorine.

2. (Ph. L.) Hydrochloric acid, 1 pint; water, 1 quart; and zinc (in small pieces), 7 oz.; when the effervescence is nearly finished, apply heat until bubbles cease to be evolved; decant the clear, and evaporate to dryness; fuse the resulting ma.s.s in a lightly covered crucible, by a red heat, pour it out on a flat smooth stone, and, when cold, break it into small pieces, or cast it into rods in iron moulds, and preserve it in a well-stoppered bottle.

3. (B. P.) Put 16 oz. of granulated zinc into a porcelain basin, add by degrees 44 fl. oz. of hydrochloric acid previously mixed with 1 pint of distilled water, and aid the action by gently warming it on a sand-bath, until gas is no longer evolved. Boil for half an hour, supplying the water lost by evaporation, and allow it to stand on the cool part of the sand-bath for 24 hours, stirring frequently. Filter the product into a gallon bottle, and pour in solution of chlorine q. s. by degrees, with frequent agitation, until the fluid acquires a permanent odour of chlorine. Add 1/2 oz. or a sufficient quant.i.ty of carbonate of zinc, in small quant.i.ties at a time, and with renewed agitation, until a brown sediment appears. Filter through paper into a porcelain basin, and evaporate until a portion of the liquid, withdrawn on the end of a gla.s.s rod and cooled, forms an opaque white solid. Pour it out now into proper moulds, and when the salt has solidified, but before it has cooled, place it in closely-stoppered bottles.

4. (In SOLUTION).--_a._ (LIQUOR ZINCI CHLORIDI--Ph. D.) Hydrochloric acid and water, of each 2-1/2 pints; sheet zinc, 1 lb.; dissolve, filter through calico, add of hypochlorite of calcium, 1 fl. oz., and evaporate, by boiling, to a pint; when cold, pour it into a bottle, add of prepared chalk, 1 oz., and water, q. s. to make the whole measure 1 quart; agitate occasionally for 24 hours, decant or filter, and preserve the liquid in a stoppered bottle. Sp. gr. 1593. See SOLUTIONS.

_b._ (E. Parrish.) Granulated zinc, 4 lbs.; hydrochloric acid, 4 lbs., or q. s.; water, 9 quarts; dissolve, avoiding excess of acid. The solution contains 1 in 12 of chloride of zinc. Recommended as of the proper strength for a disinfectant.

_Prop., &c._ When pure, a colourless, amorphous ma.s.s or crystals; generally a whitish-gray, semi-transparent ma.s.s, having the consistence of wax; fusible; volatile at strong heat, condensing in acicular crystals; freely soluble in alcohol, ether, and water; highly deliquescent; coagulates alb.u.men and gelatin, and corrodes animal substances. The solution possesses the same properties in a minor degree.

_Pur._ From the aqueous solution, hydrosulphuric acid or ferrocyanide of pota.s.sium being dropped in, a precipitate is thrown down. What is thrown down by ammonia or hydrate of pota.s.sium from the same solution is white, and is redissolved by either precipitant in excess. The precipitate thrown down by the carbonate of either ammonium or pota.s.sium is (also) white, but is not redissolved when these are added in excess.

_Uses, &c._ Dry chloride of zinc is chiefly used as a caustic, for which it is highly recommended by Voght, Canquoin, and others. It is more powerful than chloride of antimony, and its action extends deeper than does nitrate of silver, whilst it exercises an influence over the vital actions of neighbouring parts. The sore is generally healthy after the separation of the eschar, and no const.i.tutional disorder ensues. It has been given in scrofula, epilepsy, ch.o.r.ea, &c.; and, combined with hydrocyanic acid, in facial neuralgia.--_Dose_, 1/2 gr. to 2 gr.; externally, as a lotion, 2 to 3 gr. to water, 1 oz. In large doses it is poisonous.

The solution is also used as a caustic, but chiefly as a disinfectant and deodorizer, _e.g._ as Sir Wm. Burnett's Fluid and Professor Tuson's 'Sporokton,' of which it is one of the very best, possessing, as it does, the power of rapidly decomposing sulphide of ammonium and of rendering inert the virus of infectious diseases.

=Zinc, Cy'anide of.= ZnCy_{2}. _Syn._ CYANURET OF ZINC; ZINCI CYANIDUM, ZINCI CYANURETUM, L. _Prep._ (P. Cod.) Add a solution of cyanide of pota.s.sium to another of pure sulphate of zinc; wash, and dry the precipitate.--_Dose_, 1/8 to 1 gr., twice a day; in epilepsy, hysteria, and other nervous affections, heartburn, worms, &c.; and as a subst.i.tute for hydro-cyanic acid.

=Zinc, Ferrocy'anide of.= Zn_{2}FeCy_{6}. _Syn._ ZINCI FERROCYANIDUM, L.

_Prep._ By adding a hot solution of ferrocyanide of pota.s.sium to a hot and strong solution of pure sulphate of zinc, and was.h.i.+ng, and drying the precipitate. White.--_Dose_, 1 to 4 gr.; in the same cases as the last.

=Zinc, I'odide of.= ZnI_{2}. _Syn._ HYDRIODATE OF ZINC; ZINCI IODIDUM, ZINCI HYDRIODAS, L. _Prep._ 1. (Duflos.) Iodine, 2 parts; granulated zinc, 1 part; water, 4 parts; proceed as for ferrous iodide, only employing a gla.s.s or porcelain vessel.

2. (Magendie.) Iodine, 17 parts; zinc (in powder), 20 parts; mix, and sublime in a matra.s.s.

_Prop., &c._ Deliquescent. Chiefly used externally; 15 gr. to water, 6 fl.

oz., as a collyrium in scrofulous inflammation of the eye (Poulet); 1 dr.

to lard, 1 oz., as a powerful resolvent in scrofulous and other glandular swellings, rubbed on the part twice a day. (Ure.)

=Zinc, Lac'tate of.= Zn(C_{3}H_{5}O_{2})_{2}. _Syn._ ZINCI LACTAS, L.

Prepared from zinc in the same way as ferrous lactate is from iron.

=Zinc, Ox'ide of.= _Syn._ PROTOXIDE OF ZINC; ZINCI OXYDUM (B. P., Ph. L., E., & D.), L. _Prep._ 1. (Ph. L.) Sulphate of zinc (pure), 1 lb.; carbonate of ammonium, 6-1/2 oz.; dissolve each separately in 6 quarts of water, filter, mix the solutions, well wash the precipitate with water, and calcine it for 2 hours in a strong fire. The Ph. E. is nearly similar.

2. (Ph. D., B. P.) Place carbonate of zinc in a covered clay crucible, and expose it to a very low red heat, until a portion taken from the centre of the ma.s.s ceases to effervesce on being dropped into dilute sulphuric acid.

_Prop., &c._ A white, tasteless powder; insoluble in water; freely soluble in acids, the solution yielding colourless and easily crystallisable salts; strongly basic.

_Uses, &c._ It is tonic and antispasmodic, and has been advantageously used in ch.o.r.ea, epilepsy, and other nervous and spasmodic affections.--_Dose_, 1 to 6 gr., twice a day. It is also used as a dusting powder, and to make an ointment. It has been proposed as a subst.i.tute for white lead in painting, than which it covers better, but dries slower, and hence requires the addition of dried white vitriol. This oxide is the only compound which zinc forms with oxygen.

=Zinc, Phosphide.= Fragments of pure distilled zinc are introduced into a tubulated stoneware retort, so as to occupy about one fourth of its capacity; the retort is placed in an ordinary furnace, and a current of dry carbonic acid is pa.s.sed into it through the neck. Over the tubulure is placed a crucible cover, so as to close the orifice incompletely, and allow the carbonic acid, after traversing the retort, to escape. When the zinc enters into ebullition, small fragments of previously-dried phosphorus are successively thrown in through the tubulure. The cover is removed and returned after each addition to prevent loss of phosphorus.

From time to time it is necessary to break the crust of phosphorus formed, in order to expose a new layer of metal to the action of the phosphorus.

The operation is terminated by increasing the heat strongly--a precaution that is indispensable, in order to separate as completely as possible the zinc phosphide from the metallic b.u.t.ton of nearly pure zinc, which collects at the bottom of the retort. Further, the zinc phosphide should be reduced to very fine powder, and the fragments which resist the action of the metal, however slightly, should be reserved for another operation.

The product pulverises the more readily in proportion as it approaches more closely the formula P_{2}Zn_{3}. In this state it resembles iron reduced by hydrogen, and only thus should it be used by pharmaceutists. It is completely soluble in hydrochloric acid.[274]

[Footnote 274: From 'Formulae for New Medicaments,' adopted by the Paris Pharmaceutical Society.]

=Zinc, Sulphate of.= ZnSO_{4}. _Syn._ WHITE COPPERAS*; WHITE VITRIOL*; ZINCI SULPHUS (B. P., Ph. L., E., & D.), L. _Prep._ 1. (Ph. L.) Granulated zinc, 5 oz.; diluted sulphuric acid, 1 quart; dissolve, filter. Evaporate to a pellicle, and set it aside to crystallise.

2. (Ph. D.) Zinc (laminated or granulated), 4 oz.; sulphuric acid, 3 fl.

oz.; water, 1 pint; mix in a porcelain capsule, and, when gas ceases to be evolved, boil for 10 minutes, filter through calico, and evaporate the filtrate to dryness; dissolve the dry salt in water, 1 pint; frequently agitate the solution, when cold, during 6 hours, with prepared chalk, 1/4 oz.; next filter, acidulate the filtrate with nitric acid and dilute sulphuric acid, of each 1 fl. dr.; evaporate until a pellicle forms on the surface, and set it aside to crystallise; dry the crystals on bibulous paper, without heat, and preserve them in a bottle. More crystals may be obtained from the mother-liquor.

3. (B. P.) Pour 12 fl. oz. of sulphuric acid, previously mixed with 4 pints of distilled water, on 16 oz. of granulated zinc contained in a porcelain basin, and when effervescence has nearly ceased, aid the action by a gentle heat. Filter the fluid into a gallon bottle, and add, gradually, with constant agitation, solution of chlorine until the fluid acquires a permanent odour of chlorine. Add now, with continued agitation, 1/2 oz. or q. s. of carbonate of zinc, until a brown precipitate appears; let it settle, filter the solution, evaporate till a pellicle forms on the surface, and set aside to crystallise. Dry the crystals by exposure to air on filtering paper placed on porous tiles. More crystals may be obtained by again evaporating the mother-liquor.

4. The common sulphate of zinc of commerce frequently contains copper, cadmium, lead, iron, and manganese, and nearly always one or more of them.

By digesting its concentrated solution for some time with metallic zinc, it may be freed from copper, lead, and cadmium, for these metals are all reduced and precipitated in a metallic state; or, the acidulated solution may be treated with sulphuretted hydrogen as long as any precipitate forms. In order to separate the iron, chlorine gas may be pa.s.sed into the solution, by which the iron is converted into the ferrous chloride; if this solution be exposed to the air for a length of time, it absorbs oxygen, and oxide of iron is deposited as a yellow powder, from which the solution must be filtered. When the sulphate contains manganese, which is not very often the case, the solution must be boiled up a few times with purified charcoal, filtered, and evaporated. ('Jour. fur prakt. Chem.') The product of each of the above formulae is nearly chemically pure.

5. (_Commercial._) The crude sulphate of zinc (white copperas, or white vitriol, of the shops) is prepared by roasting native sulphide of zinc (zinc blende) in a reverberatory furnace, exposing the calcined ma.s.s to the air and humidity for some time, then lixiviating it, and evaporating the resulting solution until it forms a white semi-crystalline ma.s.s on cooling.

_Prop._ Pure sulphate of zinc forms inodorous, colourless, transparent, quadrangular prisms, closely resembling in appearance those of Epsom salt, which effloresce slightly in the air, and contains 7 equiv. of water; it has a slightly acidulous and very styptic metallic taste; the crystals dissolve in 2-1/2 parts of cold and in less than their own weight of boiling water; they are insoluble in alcohol. The crude sulphate of zinc of commerce (white vitriol) occurs in irregular granular ma.s.ses, which somewhat resemble loaf sugar.

When a solution of this salt, in 6 of water, is boiled with a little nitric acid, and a solution of ammonia is then added until the oxide of zinc at first precipitated is all redissolved, no yellow precipitate remains, or a trace only, and the solution is colourless.

_Uses._ In medicine, as a tonic, antispasmodic, &c.; in doses of 1 to 2 gr., twice daily; as an emetic, 10 to 30 gr. In large doses it is poisonous. It has been employed with benefit in dyspepsia, fluor albus, ch.o.r.ea, epilepsy, hooping-cough, and other convulsive and nervous affections, generally combined with bitters, foxglove, hemlock, henbane, or opium. As an emetic, it acts almost immediately, and is therefore well suited to empty the stomach at the commencement of a fit of ague, and in cases of poisoning, &c. It is also extensively used externally, to form astringent and repellant collyria, injections and lotions.

=Zinc, Sulpho-carbolate.= The acid prepared as in sulpho-carbolate of soda (which _see_) is saturated by aid of a gentle heat with oxide of zinc, filtered, and crystals allowed to form. The crystals should be dried by exposure to the air.

=Zinc, Vale"rianate of.= Zn(C_{5}H_{9}O_{2})_{2}. _Syn._ ZINCI VALERIANAS (B. P., Ph. D.) _Prep._ (Ph. D.) Valerianate of sodium, 2-1/2 oz., and sulphate of zinc, 2 oz. 7 dr., are each separately dissolved in distilled water, 1 pint; the solutions are then heated to 200 Fahr., mixed, and the resulting crystals skimmed off; the liquid is next evaporated at a temperature not higher than 200, until it measures 4 fl. oz., the crystals, as they form, being removed from the surface; the salt thus obtained is steeped, for an hour, in distilled water, just sufficient to cover it, after which the whole is transferred to a paper filter, on which it is at first drained, and then dried at a heat not exceeding 100.

_Prop., &c._ Brilliant white, pearly scales; very light; astringent; smells strongly of valerianic acid; only slightly soluble in cold water, more so in hot water, and freely soluble in alcohol and ether; exposure to heat rapidly decomposes it; exposure to the air also decomposes it, but more slowly. It is regarded as powerfully antispasmodic and tonic.--_Dose_, 1 to 3 gr., thrice daily, made into pills; in neuralgia, tic douloureux, nervous headaches (more particularly hemicrania), hysteria, palpitation of the heart, vertigo, ch.o.r.ea, epilepsy, &c.

_Obs._ Butyrate of zinc, scented with valerianic acid, which is often sold for the above compound, may be detected by distilling it with sulphuric acid; the distillate, tested with a strong solution of acetate of copper, gives a bluish-white precipitate if it contains butyric acid. The valerianate is distinguished from the other salts of zinc by its extreme lightness.

=ZINC-E'THYL.= Zn(C_{2}H_{5})_{2}. A curious liquid body, discovered by Dr Frankland, and formed, along with iodide of zinc, when iodide of ethyl is heated with pure zinc in a sealed gla.s.s tube. The mixed white product, by distillation in a current of hydrogen, yields pure zinc-ethyl. It is a highly volatile liquid, having a rather disagreeable odour, and so rapidly decomposed by contact with the air that it takes fire. Water resolves it into hydride of ethyl, and other products.

=ZINC-ME'THYL.= Zn(CH_{3})_{2}. Obtained by the action of zinc upon iodide of methyl, as zinc-ethyl. It takes fire on coming in contact with the air.

=ZINC'ING.= _Syn._ ZINKING. Vessels of copper and bra.s.s may be covered with a firmly adherent layer of pure zinc, by boiling them in a solution of chloride of zinc, pure zinc turnings being at the same time present in considerable excess. The same object may be effected by means of zinc and a solution of chloride of ammonium or hydrate of pota.s.sium.

The variety of zinced iron commonly known by the name of 'galvanised iron'

is prepared by immersing the sheets of metal, previously scoured and cleaned with dilute hydrochloric acid, in a bath of melted zinc covered with powdered sal ammoniac, and moving them about until they are sufficiently coated.

=ZINCOG'RAPHY.= An art closely resembling lithography, in which plates of zinc are subst.i.tuted for slabs of stone.

=ZIR'CON.= See GEMS.

=ZIRCONIUM.= Zr. _Syn._ The oxide of this metal, a white pulverulent earth, discovered in the mineral gargon or zircon of Ceylon, by Klaproth, in 1789. It has since been found in the hyacinth.

_Prep._ The stone is calcined and thrown into cold water, and then powdered in an agate mortar; the powder is mixed with 9 parts of pure hydrate of pota.s.sium, and the mixture projected, by spoonfuls, into a red-hot crucible, care being taken that each portion is fused before another is added; after fusion, with an increased heat, for an hour and a half, the whole is allowed to cool; the calcined ma.s.s is next powdered, and boiled in water; the insoluble portion is then dissolved in hydrochloric acid, and the solution heated, that the silicic acid may fall down, after which the zirconia is precipitated with hydrate of pota.s.sium; or, the zirconia may be precipitated with carbonate of sodium, and the carbonic acid expelled by heat.

From this, metallic zirconium is obtained by heating in a gla.s.s tube, with a spirit lamp, a mixture of pota.s.sium and the double fluoride of zirconium and pota.s.sium, carefully dried; the product is washed with water, and digested for some time in dilute hydrochloric acid.

_Prop., &c._ A black powder; it acquires a feeble metallic l.u.s.tre under the burnisher, and takes fire when heated in the air. It has not been thoroughly examined.

Oxide of zirconium, or zirconia, ZrO_{2}, has neither taste nor odour, is insoluble in water, and forms salts with the acids. It is distinguished from all the other earths, except thorina, by being precipitated when any of the neutral salts of zirconium are boiled with a saturated solution of sulphate of pota.s.sium. The salts of zirconium are distinguished from those of aluminium and glucinium by being precipitated by all the pure alkalies, and by being insoluble when they are added in excess. The precipitated hydrate and carbonate are readily soluble in acids.