Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 283

[Ill.u.s.tration: Oxalate of lime. (Beale.)]

[Ill.u.s.tration]

_Cystine._ Cystine is an occasional ingredient in urine, when it occurs as a whitish precipitate crystallised in hexagonal plates. At other times, but not so frequently, it is met with dissolved in the urine. It may be separated from the urine holding it in solution by the addition of an excess of acetic acid. Under the microscope cystine bears somewhat of a resemblance to uric acid, from which, however, it differs when under treatment with ammonia. When ammonia is added to cystine the cystine dissolves, but by the spontaneous evaporation of the ammonia remains behind in its original form; whilst, if the ammonia be allowed to escape under the same circ.u.mstance from the urate of ammonia which has been formed, this remains behind as an amorphous ma.s.s. Ammonia, therefore, dissolves the cystine without entering into chemical union with it. Potash also readily dissolves cystine, as do also oxalic acid and the strong mineral acids. It is, however, insoluble in boiling water, in weak hydrochloric acid, and, as we have seen, in acetic acid.

_Obs._ In the examination of urine it is important that the investigation should be conducted upon a portion taken from _the whole of the urine excreted during twenty-four hours_, and not on an isolated quant.i.ty voided at any particular time.

The compiler of the present article has to acknowledge his indebtedness to Dr Lionel Beale's very valuable and exhaustive work, 'Kidney Diseases, Urinary Deposits, &c.,' as well as to Dr W. Roberts's excellent book, 'Urinary and Renal Diseases,' to both of which volumes the reader, desirous of further and more explicit information on the subject, is referred.

=URINOM'ETER.= An hydrometer adapted to determining the density of urine.

That of Dr Prout is the simplest and best. Urinometers should always be tested by placing them in distilled water at 60 Fahr. from 1015 to 1025 Beale.

=URN POWDER.= Crocus martis, or jeweller's rouge.

=URTICAR'IA.= See RASH.

=US'QUEBAUGH.= _Syn._ ESCUBAC. Literally, mad water, the Irish name of which, 'whisky,' is a corruption. At the present time it is applied to a strong cordial spirit, much drunk in Ireland, and made in the greatest perfection at Drogheda.

_Prep._ 1. Brandy or proof spirit, 3 galls.; dates (without their kernels) and raisins, of each, bruised, 1/4 lb.; juniper berries, bruised, 1 oz.; mace and cloves, of each 3/4 oz.; coriander and aniseed, of each 1/2 oz.; cinnamon, 1/4 oz.; macerate, with frequent agitation, for 14 days, then filter, and add of capillaire or simple syrup, 1 gall.

2. Pimento and caraways, of each 3 oz.; mace, cloves, and nutmegs, of each 2 oz; aniseed, corianders, and angelica root, of each 8 oz.; raisins, stoned and bruised, 14 lbs.; proof spirit, 9 galls.; digest as before, then press, filter, or clarify, and add of simple syrup, q. s. Should it turn milky, add a little strong spirit, or clarify it with alum, or filter through magnesia.

_Obs._ Usquebaugh is either coloured yellow with saffron (about 1/4 oz.

per gall.), or green with sap-green (about 1/2 oz. per gall.); either being added to the other ingredients before maceration in the spirit.

=UVA URSI.= The _Arctostaphylus Uva Ursi_ (the Bearberry) is an indigenous plant, the leaves of which are employed in medicine. Bearberry leaves contain a large percentage of tannic acid, with a small quant.i.ty of gallic acid, some resin, and a little volatile oil and extractive, together with a crystallisable principle named _arbutin_, which is said to be a very powerful diuretic. Another crystallisable resinous body named _arbutin_ has also been discovered in them. Bearberry leaves either in the form of powder, infusion, or extract, are chiefly used in chronic diseases of the bladder, in which there is an abnormal secretion of mucus, such as _catarrhus vesicae_, but neither acute nor active inflammation.

=VACCINA'TION.= See COW-POX. (POX.)

=VAC'CINE MATTER.= _Syn._ LYMPHA VACCINIae, L. This is collected either upon the points of lancet-like pieces of ivory, or by opening the pustule, and applying a small gla.s.s ball and tube (like those called by the boys in London candle-pops, or fire-pops) to the orifice, expelling part of the air in the ball by bringing a lighted taper near it; then, withdrawing the taper, the matter is sucked into the ball, in which it may be sealed up hermetically or cemented, and thus kept for a length of time. It is, however, now generally preserved between two small pieces of gla.s.s, or in straight capillary gla.s.s tubes. It is said that cotton thread is a convenient and efficient vehicle. The matter may be liquefied with a little clean water before application. A degree of heat scarcely higher than that of the blood lessens its efficacy.

=VAC'UUM.= Empty s.p.a.ce; a portion of s.p.a.ce void of matter. For experimental and manufacturing purposes, a sufficient vacuum is produced either by means of the air-pump, or by filling an inclosed s.p.a.ce by steam, which is then condensed by the application of cold. Evaporation proceeds much more rapidly, and liquids boil at much lower temperatures in an exhausted receiver than when exposed to the air. Thus, under ordinary circ.u.mstances, in the air, ether boils at 96, alcohol at 177, and Water at 212 Fahr.; but in vacuo water boils at about 88, alcohol at 56, and ether at -20 Fahr. In the best vacuum obtainable by a powerful air-pump, water placed over oil of vitriol, to absorb the aqueous vapour as it forms, will often enter into violent ebullition whilst ice is in the act of formation on its surface. The reduction of the boiling-point with reduced pressure is practically taken advantage of by the pharmaceutist in the preparation of extracts, by the sugar refiner in the evaporation of his syrups, by the distiller in the production of certain liqueurs, and by the chemist in a variety of processes of interest or utility. See EXTRACTS, EVAPORATION, REFRIGERATION, &c.

=VALE"RIAN.= _Syn._ VALERIANae RADIX (B. P.), VALERIANae RADIX, VALERIANA (Ph. L. E. & D.), L. "The root of the wild plant _Valeriana officinalis_ (Linn.), or wild valerian." (Ph. L.) An excitant, antispasmodic, tonic, and emmenagogue, not only acting on the secretions, but exercising a specific influence over the cerebro-spinal system, and in large quant.i.ties producing agitation, mental exaltation, and even intoxication.--_Dose_, 10 to 30 or 40 gr., thrice daily; in hysteria, epilepsy, headache (affecting only one side), morbid nervous sensibility, &c. Even the odour of it exerts a species of fascination over cats.

=VALERIAN'IC ACID.= HC_{5}H_{9}O_{2}. _Syn._ VALERIC ACID; ACIDUM VALERIANIc.u.m, A. VALERIc.u.m, L. _Prep._ 1. A mixture of potato oil or corn-spirit oil (hydrated oxide of amyl) with about 10 times its weight of quicklime and hydrate of pota.s.sa in equal proportions, placed in a gla.s.s flask, is kept heated to about 400 Fahr., for 10 or 12 hours, by means of a bath of oil or fusible metal; the nearly white solid residuum is mixed with water, an excess of sulphuric acid added to the mixture, and the whole subjected to distillation; the distillate is supersaturated with pota.s.sa, evaporated nearly to dryness, to dissipate any undecomposed potato oil, and then mixed with weak sulphuric acid in excess; a light oily liquid (terhydrated valerianic acid) separates, which by cautious rectification, yields at first water containing a little acid, and afterwards pure monohydrated valerianic acid, which is perfectly identical with that prepared from valerian root.

2. (Ph. D.) See VALERIANATE OF SODIUM. This is a most economical process.

_Prop., &c._ A limpid oily liquid, smelling strongly of valerian root; it has an acid taste and reaction, and leaves a sensation of sweetness and a white spot on the tongue; is inflammable; boils at 347; is freely soluble in alcohol and ether; dissolves in 30 parts of water, and forms salts called valerianates, most of which have a sweetish taste, are soluble, and uncrystallisable; sp. gr. 937; placed in contact with water, it absorbs a portion of it, and is converted into the terhydrated acid, with increase of sp. gr., and reduction of the boiling-point.

=VALE"RIC ACID.= See VALERIANIC ACID.

=VALO'NIA.= The cup of a large species of acorn, imported from the Levant.

Used in tanning leather.

=VANAD'IC ACID.= V_{2}O_{2}. _Syn._ VANADIC ANHYDRIDE, TEROXIDE OF V.; ACIDUM VANADIc.u.m, L. _Prep._ (Johnston.) From the native vanadate of lead, by dissolving it in nitric acid, pa.s.sing sulphuretted hydrogen through the solution, to throw down lead and a.r.s.enic, filtering, and evaporating the resulting blue liquid to dryness; the residuum is then dissolved in a solution of ammonia, and a piece of sal ammoniac, considerably larger than can be dissolved, introduced; as the latter dissolves, a pulverulent precipitate of vanadate of ammonium is formed, which must be washed, first in a solution of sal ammoniac, and then in alcohol of 860; by exposing this salt, in an open platinum crucible, to a heat a little below redness, and keeping it constantly stirred, until it acquires a dark red colour, pure vanadic acid is obtained.

_Prep., &c._ Vanadic acid is orange coloured, scarcely soluble in water, and forms, with the alkaline bases, soluble salts called vanadates; and with the other bases sparingly soluble salts. All of these have an orange or yellow colour. "Vanadate of ammonia mixed with solution of galls forms a black fluid, which is the best writing ink hitherto known. The quant.i.ty of salt required for this purpose is very small; the writing is perfectly black, and not obliterated by alkalies, acids, chlorine, or other reagents," (Ure.)

=VANA'DIUM.= V. A rare metal discovered by Sefstom, in 1830. in some Swedish iron extracted from an iron mine near Jonkoping. It has since been found in a Vanadinite lead ore met with in Scotland, Zimpanan in Mexico, and Chili, and in the iron slag of Staffords.h.i.+re. Of late years a more abundant source of Vanadium has been discovered by Professor Roscoe in the cupriferous stratum of the New Red Sandstone at Alderley Edge in Ches.h.i.+re.

There are four, and possibly five oxides of this element.

=Vanadic oxychloride.= _Syn._ VANADIC OXYTRICHLORIDE. (VOCl_{3}.) Roscoe states there are several oxychlorides of vanadium, which, however, have not been studied. The most interesting of them is the oxytrichloride, which corresponds to the phosphorous oxychloride. This oxytrichloride is a yellow fuming liquid, which is instantly decomposed by water into vanadic and hydrochloric acids. The oxytrichloride may be obtained by heating vanadic anhydride and charcoal (mixed together) in a current of hydrogen, after which it is heated in a current of dry chlorine. An easier method is by pa.s.sing dry chlorine over the sesquioxide of vanadium.

=Vanadic pentoxide.= _Syn._ VANADIC ANHYDRIDE (V_{2}O_{5}.). At a red hot heat this oxide fuses, and on cooling, crystallises in rhombic prisms. It is but little soluble in water; the aqueous solution, which is of a yellow tint, is strongly acid, and produces a marked reddening effect on litmus.

Vanadic anhydride forms both normal and acid salts. The ammonic vanadiate (Roscoe's meta vanadiate) is the chief source of the acid. This salt may be obtained by adding pieces of sal ammoniac to a crude solution of pota.s.sic vanadiate, the resulting ammonic vanadiate being insoluble in a saturated solution of sal ammoniac, is deposited in small crystalline grains. The vanadic anhydride may be obtained from the ammonic vanadiate by heating an aqueous solution of the salt in the open air, when the ammonia is driven off, and the vanadic anhydride is left behind. The acid ammonic vanadiate, mixed with tincture of galls, makes a very durable writing ink, unacted upon either by alkalies or chlorine. Acids turn such blue without, however, destroying it.

=Vanadic triox'ide.= (V_{2}O_{2}.), is the _Vanadyl_ of Roscoe, who obtained it in the form of a grey metallic-looking powder, by the transmission of a current of dry hydrogen charged with the vapours of oxychloride of Vanadium, through a tube containing ignited charcoal. It dissolves in dilute acids, with evolution of hydrogen. Solutions of its salts are lavender coloured. Berzelius regarded this oxide as a metal.

_Tests._ The vanadiates mostly occur of a red or yellow colour. When treated with sulphuretted hydrogen, they yield a solution of a fine blue colour, a reaction that distinguishes them from the chromates, which, under similar treatment, would give a green liquid. When mixed with borax and exposed to the reducing flame of the blowpipe, compounds containing vanadium give a green gla.s.s, which turns to yellow in the oxidizing flame.

Professor Roscoe, to whose researches we are indebted for all the chemical knowledge we possess respecting vanadium, says:--"All the main facts now established in connection with the chemical department of this element proved it to bear a strong a.n.a.logy to the elements phosphorus and a.r.s.enic; in fact, it occupied a previously vacant place in a well-defined group of triad, or, as some chemists prefer to consider them, pentad elements.

There was a property of vanadium in virtue of which it might ultimately obtain considerable importance in the arts, though in the present infancy of the history of the metal it was difficult to foretell this with any certainty. This property was the power of forming a permanent black for dyeing purposes. The black produced by the action of vanadium had the advantage over copper and aniline blacks, viz. that it was permanent, whereas the latter were liable to turn green. This application of an element that was first introduced into notice as a chemical curiosity furnished one more example of the importance of original scientific investigation. However far a newly discovered substance might seem to be removed from purposes of practical utility, we never know at what moment it might be turned to account for the benefit of the human race."

=VANIL'LA.= _Syn._ VANILLE, Fr. The dried pods of various species of Vanilla, a genus of the natural order _Orchidaceae_. It is chiefly used in the manufacture of chocolate and perfumery. As a medicine it is much employed on the Continent as an aromatic stimulant and neurotic.--_Dose_, 6 to 12 gr.; in asthenic fevers, hysteria, hypochondriasis, impotency, &c.

Vanilla is reduced to powder (PULVIS VANILLae; POUDRE DE VANILLE) by slicing it, and triturating the fragments with twice or thrice their weight of well-dried lump sugar. For SUCRE DE VANILLE, 11 parts of sugar are employed.

The following table given by Messrs Tieman and Harmann, in the _Journal of the Berlin Chemical Society_, represents the quant.i.ties of Vanillin (the aromatic principle of Vanilla) contained in that substance, as obtained from different sources:--

Vanillin per Cent.

Mexican Vanilla (1873, harvest) 169 Mexican Vanilla (1874, harvest) 186 Mexican Vanilla Medium quality 132 Bourbon, best quality (1874-75) 191 Bourbon, (1874-75) 197 Bourbon, (1874-75) 290 Bourbon, Small medium (1874-75) 155 Java, best quality (1873) 275 Java, best quality (1874) 156

=VANILLIN.= A crystallised substance obtained from pine juice by Messrs Tiemann and Harmann. It has been shown to be identical with the aromatic principle of Vanilla.

In a paper read before the Royal Society the authors have described the process by which vanillin was artificially prepared by them. They state that the sap of the cambium of coniferous trees contains a beautiful crystalline glucoside coniferine, which was discovered by Kartig, and examined some years ago by Rubel, who arrived at the formula C_{24}H_{32}O_{12} + 3 Aq. A minute study of this compound leads us to represent the molecule of coniferine by the expression, C_{16}H_{22}O_{3} 2 Aq., the per centages of which nearly coincide with the theoretical values of Kubel's formula.

Submitted to fermentation with emulsine, coniferine splits into sugar, and a splendid compound, crystallising in prisms, which fuse at 73. This body is easily soluble in ether, less so in alcohol, almost insoluble in water; its composition is represented by the formula C_{10}H_{12}O_{3}. The change is represented by the equation--

C_{16}H_{22}O_{8} + H_{2}O = C_{6}H_{12}O_{6} + C_{10}H_{12}O_{3}.

Under the influence of oxidising agents, the product of fermentation undergoes a remarkable metamorphosis. On boiling it with a mixture of pota.s.sium b.i.+.c.hromate and sulphuric acid, there pa.s.ses with the vapour of water in the first place ethylic aldehyd, and subsequently an acid compound soluble in water, from which it may be removed by ether. On evaporating the ethereal solution, crystals in stellar groups are left behind, which fuse at 81. These crystals have the taste and odour of vanilla.

An accurate comparative examination has proved them to be identical with the crystalline substance which const.i.tutes the aroma of vanilla, and which is often seen covering the surface of vanilla pods.

On a.n.a.lysis, the crystals we obtained were found to contain C_{8}H_{8}O_{3}. This is exactly the composition which recent researches of Carles have established for the aromatic principle of vanilla. The transformation of the crystalline product of fermentation into vanillin is represented by the following equation:

C_{10}H_{12}O_{3} + O = C_{2}H_{4}O + C_{8}H_{8}O_{3}.

To remove all doubt regarding the ident.i.ty of artificial vanillin with the natural compound, we have transformed the former into a series of salts, which have the general formula, C_{8}H_{7}MO_{3}, and into two subst.i.tution products, C_{8}H_{7}BrO_{31}, and C_{8}H_{7}TO_{3}, both of which had previously been prepared by Carles from the natural compound.

=VAN SWIETEN'S SOLUTION.= Contains 1/1000th part of its weight of corrosive sublimate; or 1/2 gr. per fl. oz.

=VAPOUR.= Vapours are really gases, and amenable to substantially the same physical laws; as ordinarily understood, however, the difference between a gas and a vapour is the following:--A gas is a form of matter which exists, at ordinary temperatures and pressures, in a state of vapour; whilst a vapour has been formed by the application of heat to a body usually existing in the solid or liquid form; gases, therefore, differ from vapours only in being derived from bodies which, in the solid or liquid form, boil at very much lower temperatures.

=Vapour of Ammonia.= _Syn._ VAPOR AMMONIae. (St Th. Hosp.) Solution of ammonia (959), water, equal parts. A teaspoonful in a pint of water at 80 F. for each inhalation. In chronic laryngitis and functional aphonia.