Cooley's Cyclopaedia of Practical Receipts Volume I Part 87

=BEN'ZOL= (-zole). C_{6}H_{6}. [_benz_(oin)-_oleum._] _Syn._ BEN'ZENE*, BEN'ZINE, BEN'ZOLE*, HYDRIDE OF PHE'NY??L*, PHE'NE, &c.; BENZO'LEUM, L.; BENZINE, Fr.; BENZoL, Ger. A peculiar ethereal hydrocarbon discovered, by Faraday, among the products of the destructive distillation of whale oil and other organic substances (A.D. 1825); and subsequently shown, by Mitscherlich, to form the princ.i.p.al ingredient in the distillate procured by the action of heat on a mixture of benzoic acid and hydrate of lime. In 1849, Mr C. B. Mansfield[154] discovered its presence in coal-tar naphtha, from which the benzol of commerce is now chiefly, if not wholly, obtained.

[Footnote 154: This unfortunate chemist lost his life (Feb. 25, 1855), in consequence of being severely burned whilst experimenting on benzol.]

_Prep._ 1. PURE:--_a._ A mixture of benzoic acid, 1 part; fresh-slaked lime, 3 parts; is submitted, in a coated gla.s.s or earthenware retort, to a heat slowly raised to redness; the oily portion of the resulting distillate is then separated from the water, and carefully rectified, with the proper precautions, at a temperature not exceeding 190 Fahr. The product is usually stated to be pure benzol; but to ensure this it may be submitted to one refrigeration and rectification, in the manner and at the temperature noticed below.

_b._ From good commercial benzol, agitated with 1-4th or 1-5th of its weight of concentrated sulphuric acid, and, after repose and decantation, rectified at a temperature under 195 Fahr.; the resulting distillate is exposed to a temperature below[155] 32 Fahr., and the ma.s.s of crystals that form are thrown on a funnel, kept at the same temperature, to drain, after which they are pressed between folds of bibulous paper,[156] and then allowed to liquefy by simple exposure, in a close vessel, to the ordinary temperature of the atmosphere. The product, after rectification at a temperature not exceeding 190, is nearly pure benzol. It may be rendered absolutely pure by repeating the refrigeration a second and a third time, followed by a final rectification at 180-185 Fahr.

[Footnote 155: Preferably considerably below. If the distillate be not rich in benzol, a temperature so low as 8 or 10, or even 4-5, Fahr. may be necessary or, at all events, advantageous.]

[Footnote 156: Filtration under pressure is thought by some chemists to be preferable. For this purpose a 'Beart's Coffee-pot' (or a similarly constructed apparatus), was often employed by Mansfield, and is recommended by Prof. Muspratt.]

2. COMMERCIAL:--By submitting light coal-tar naphtha to distillation, either at once, or after it has been agitated with a little oil of vitriol, and decanted, care being taken that the temperature does not exceed 200 Fahr.

A drawing and description of the apparatus invented by Mansfield for the preparation of benzol from coal-tar naphtha is given below.

[Ill.u.s.tration]

A is the still placed on a furnace R; C is filled with cold water. As soon as the oil in the still boils, the vapours are condensed in B, and flow back into A; this continues until the water in C has been heated to a certain temperature, when the vapours are condensed in the cooler D, the liquid flowing at _n_ into the carboy S. As soon as the water in C begins to boil, all the substances contained in the coal-tar naphtha and volatile at 212 Fahr. are condensed and collected in S. A very pure benzol is obtained by this apparatus. By opening the tap _m_, the hydrocarbons which boil over 212 Fahr. can be rectified. The stopc.o.c.k _i_ is used for opening the still.

In the benzol works the apparatus shown below is employed.

A is the still, B the condenser, C a water-tank. At the commencement of the operation the water in C is heated by means of the steam-pipe D which communicates with the steam boiler. The tube G is attached to the still; _i_ is a contrivance for filling, _b_ for emptying it. The condensed water is carried off by means of H. By freezing benzol and pressing the solid substance obtained, it may be rendered quite pure.

[Ill.u.s.tration]

_Prop._ Pure benzol is a clear, colourless, very mobile liquid, having a strong, characteristic, and rather agreeable ethereal odour. It is neutral to test-paper; exceedingly volatile at all temperatures; insoluble in water; miscible with alcohol and with ether; highly inflammable; burns with a brilliant flame, emitting clouds of smoke, which rapidly condense and fall as a shower of fine sooty, carbonaceous matter; boils at 176 Fahr.;[157] solidifies, at 32, to a snowy white camphor-like ma.s.s, or when very slowly refrigerated, to beautiful transparent cruciform leaflets, which aggregate together into forms resembling fern-fronds; remelts at 40-1 Fahr.; and when solidifies burns, like camphor, without previous fusion. Sp. gr. 850;[158] sp. gr. of vapour, 2770.[159] It is unaffected by the ordinary hydrated acids, and has no action on the alkaline metals. Highly concentrated nitric acid readily dissolves it, and from this solution nitrobenzol is precipitated on the addition of water.

Its vapour is dangerously inflammable, and, when mixed with the air, is highly explosive. Its solvent power extends over a numerous list of substances. Commercial benzol has a less agreeable odour, and not unfrequently a slight colour, with other modifications of the properties just enumerated, depending on the relative amount of impurities contained in it.

[Footnote 157: Fownes, Mansfield, Muspratt, and others; 186--Mitscherlich 187--Mr C. G. Williams (in Ure's 'Dict. of A. M., & M.,' 5th ed.). (See next note.)]

[Footnote 158: Williams, Ure, Muspratt; 885--Fownes, Mitscherlich. The different sp. gr. and boiling-points a.s.signed to benzol, by authors, can only be accounted for by samples of different degrees of purity having probably been examined. The numbers given in the text are those not usually adopted; but we are not prepared to say, that they are definitely settled. On the contrary, we think it not unlikely that further investigations may show that the apparently greater levity of the benzole obtained from naphtha may arise from the presence of some other hydrocarbon which has. .h.i.therto escaped detection.]

[Footnote 159: Theoretically, 2738.]

_Pur._--1. It should be colourless, without action on either litmus or turmeric paper, and have the boiling-point, sp. gr.,[160] &c. already indicated:--2. A few drops thrown on a slip of gla.s.s or a piece of white paper should rapidly and entirely evaporate by simple exposure to the air without leaving a stain behind, or evolving any disagreeable or foreign odour:--3. Agitation with a little sulphuric acid should not discolour it:--4. It should not perceptibly lose weight or volume by agitation with a little cold water.

[Footnote 160: If it has a less sp. gr. than 850, it is probably adulterated with the naphtha obtained from the Torbane-hill mineral or Boghead-coal, of which the sp. gr. is only 750.]

_Detec._--1. From the physical and other properties already enumerated:--2. By converting it into aniline and then testing it accordingly. For this purpose a little of it is dissolved in concentrated nitric acid, and the nitrobenzol thus formed is precipitated by the addition of water. The fluid is then agitated with ether, to dissolve out the nitrobenzol, and the resulting ethereal solution is mixed with an equal bulk of alcohol and hydrochloric acid and a little granulated zinc at once added. Hydrogen is evolved, and by its action the nitro-compound is converted into aniline. The liquid is next alkalised with pota.s.sa in excess, and the alkaline fluid agitated with ether. The ethereal solution, on evaporation, leaves a residue (aniline), which, after the addition of a little water, may be tested with a few drops of solution of chloride of lime, when a characteristic purple colour will be developed, provided the original liquor was benzole, or contained it. In this way very minute traces of benzol may be detected.

_Uses, &c._ In its impure or commercial form, chiefly as a solvent for gutta percha and india rubber; but it leaves the first in a spongy, friable state, and the latter glutinous or sticky, unless heat is applied to it for some time; also as a solvent in the manufacture of varnishes, as a diluent in lieu of oil of turpentine, for oil-paints, as a material for the production of artificial light, &c., &c. In the pure or nearly pure form it is largely employed in the laboratory and in chemical a.n.a.lysis as a solvent of many resins,[161] mastic, wax, camphor, fat, the fixed and essential oils, sulphur, phosphorus, iodine, several of the alkaloids,[162] &c., &c. Under the name of BENZINE and BENZINE-COLLAS it has been recently extensively vended for the removal of spots of grease, paint, &c., from woven fabrics, which it does most readily and completely, without detriment to the material. As a source of artificial light it has been the subject of innumerable applications and patents. It may be burned in a 'wickless' lamp, provided a proper cap-burner be employed. Alcohol or pyroxilic spirit containing 1-3rd, or even 1-4th of it, burns with a rich white flame. Air driven through it becomes sufficiently inflammable to serve as illuminating gas; whilst ordinary coal-gas by merely pa.s.sing over it yields a flame of greatly increased brilliancy; but in all these applications the greatest possible care is necessary to prevent accidents.[163] See NAPHTHA (Coal-tar).

[Footnote 161: Anime and copal are scarcely affected by it in the fluid state, but readily dissolve in its vapour at the point of condensation.]

[Footnote 162: Particularly quinine, which it dissolves readily, but not cinchonine. Hence it is invaluable for the separation of them. It may be economically and conveniently subst.i.tuted for ether in the preparation of many alkaloids, with the advantage of being applicable in many cases in which ether cannot be employed.]

[Footnote 163: Workmen constantly exposed to the vapour of benzol are very subject to nervous irritability, and, where the apartment is ill-ventilated, even fits of nervous prostration and trembling, of a truly alarming character. In two or three cases which we have seen, the symptoms, to the inexperienced eye, closely resembled those occasionally resulting from the long-continued use of very minute doses of strychnia, or of the alcoholic extract of nux vomica.]

=Benzol, Nitrate of.= See NITRO-BENZOL.

=BENZOLINE.= A product of the fractional distillation of American rock oil. If used for burning purposes, care should always be taken to use a sponge lamp, so as to ensure the benzoline vapour (which is extremely inflammable) being well diluted with air when burnt.

=BENZOYL.= C_{7}H_{5}O. The radical of an extensive series of compounds, of which the hydride, C_{7}H_{5}OH (essential oil of bitter almonds), and benzoic acid, HC_{7}H_{5}O_{2} are the most important members.

=Benzoyl, Hy'dride of.= C_{7}H_{5}OH. _Syn._ ESSENCE OF BITTER ALMONDS, ESSENTIAL OIL OF BITTER ALMONDS, VOLATILE OIL OF BITTER ALMONDS.

_Prep._ 1. The crude oil of bitter almonds is agitated with a moderately dilute solution of protochloride of iron which has been previously mixed with fresh hydrate of lime in excess, and the whole, after having been placed in a retort connected with a suitable receiver, is subjected to distillation. The oil pa.s.ses over mixed with water, from which it is easily separated after repose. By subjecting it to a second agitation and distillation with a fresh mixture of the protochloride and hydrate, and, after careful separation from the water which distils over with it, allowing it to remain for some hours in contact with fragments of fused chloride of calcium, to free it from all traces of adhering water, the product will be nearly chemically pure, provided the whole process has been conducted with as little access of air as possible.

2. (Liebig.) Agitate the crude oil of bitter almonds with mercuric oxide in slight excess, and, after a few days' contact, rectify the oil from a little fresh oxide. The product is quite pure when the process is properly managed. The bicyanide of mercury thus formed may be either employed as such, or reconverted into oxide of mercury and hydrocyanic acid.

_Prop., &c._ A rather thin, colourless liquid, of great refractive power and characteristic and agreeable odour; soluble in 35 parts of water; miscible in all proportions with alcohol and ether; it boils at 356 Fahr.; on exposure to the air it rapidly absorbs oxygen, and becomes converted into a ma.s.s of crystallised benzoic acid; heated with solid hydrate of pota.s.sa hydrogen is evolved, and benzoate of pota.s.sium formed; with the alkaline bisulphites it forms beautiful crystalline compounds.

Its flame, and that of its vapour, is bright but very smoky. Sp. gr.

1043. It differs from the crude or common oil of bitter almonds chiefly in the absence of hydrocyanic acid, and consequently in not being poisonous. It has hence been proposed as a subst.i.tute for the crude oil as a flavouring ingredient in cookery, confectionery, liqueurs, &c.; but is unfitted for the purpose, owing to the rapid deterioration it suffers unless it be kept absolutely excluded from the air.

_Formiate of Hydride of Benzoyle._ See FORMOBENZOIC ACID.

=BER'BERINE= (-een).[164] C_{20}H_{17}NO_{4}. [Eng., Fr.] _Syn._ BAR'BERINE*, BER'BERITE* (of Thomson); BERBERI'NA, L. A substance discovered by Buchner and Herberger in the root of the common barberry shrub (_ber'beris vulga'ris_, Linn.); and subsequently, by Bodecker, in calumba-root; and more recently by Mr Perrins, in the calumba-wood (_menispermum fenestratum_) of Ceylon, which contains a considerable quant.i.ty of it.

[Footnote 164: This substance must not be confounded with BEEBERINE or BIBERINE (which _see_).]

_Prep._ 1. A soft watery extract of the root, or of the wood, is digested in rectified spirit, with trituration, as long as anything is taken up; the resulting tincture, after repose, is filtered, and the alcohol gradually distilled off until the residuum has the consistence of a thin syrup. The crystals which form as the liquid cools are drained in a funnel, washed with a few drops of ice-cold water, pressed dry in bibulous paper, and then purified by solution and crystallisation, first in rectified spirit, and next in distilled water.

2. By digesting the root, or the wood (coa.r.s.ely powdered) in rectified spirit, and then proceeding as before.

_Prop._ Berberine may be cla.s.sed with the azotised colouring substances; or, from its composition and its possessing feeble basic properties, with the alkaloids. It crystallises in fine needles, or in stellated prisms, which are yellow, odourless, very bitter-tasted, neutral to test-paper, and contain 12 equiv. of water. At 212 Fahr. it acquires a red colour; but recovers its normal yellow on cooling. A much higher temperature decomposes it, yellow vapours being evolved. It is freely soluble in boiling water and in alcohol, from either of which solutions it may be readily obtained in crystals. It requires 500 parts of water at 60 to dissolve it, and very much more at lower temperatures. Its solutions are yellow; that in alcohol appears green by reflected light. The concentrated mineral acids destroy it. Its salts are more or less soluble.

_Uses, &c._ Chiefly in medicine, in similar cases to those in which the use of calumba-root is indicated. It has been highly recommended in dyspepsia and heartburn, in disturbed action of the liver, and, combined with iron (lactate, phosphate, or hyposulphite), in chlorosis, anaemia, &c.

According to M. Altin, it is an effectual remedy for the mucal, colourless diarrha, and the derangement of the urinary secretions which commonly follow cholera.--_Dose_, 3 to 10 gr.; in larger doses it proves laxative.

See CALUMBA, &c.

=BERENIZON= (Dr Charles Wortley). A preparation for promoting the growth of the hair. Balsam of Peru 3 grammes, castor oil 3 grammes, tinct.

cinchona 4 grammes, spirit 85 grammes, rosewater 40 grammes. (Schadler.)

=BERG'AMOT.= _Syn._ BERGAMO'TA, L.; BERGAMOTE, Fr.; BERGAMOTTE, Fr., Ger.

The bergamot-lemon, or fruit of _cit'rus ber'ga'mia_; also sometimes, colloquially, the fragrant oil obtained from its rind. See OILS (Volatile).

=BERGBALSAM--MOUNTAIN BALSAM= (of G. Schmidt, Berlin). Recommended for hemorrhoids, want of appet.i.te, headache, constipation, &c. Rhubarb 2 parts, cortex frangulae 10 parts, milfoil flowers (_Achillea millefolium_) 1 part, tansy 1 part, crystallised soda 1-1/2 parts; be digested for some hours in warm water, the fluid expressed made up to 26 parts, 30 parts of sugar dissolved in it, and lastly mixed with 17 parts of rectified spirit. (Hager.)

=BER'RY= (ber'-re). _Syn._ BAC'CA (pl. _bac'cae_, -se), L.; BAIE, Fr.; BEERE, Ger. Any small succulent or pulpy fruit containing several naked seeds or granules. In _botany_, an indehiscent pericarp or seed-vessel, pulpy, many-celled, and many-seeded, the seeds being naked, and for a time connected by a slender membrane, from which they become detached at maturity, and then remain dispersed through the pulp. It is distinguished by its figure, &c., into several varieties.

The leading berries employed in domestic economy and the arts are noticed in their alphabetical places (which _see_).

=BER'YL= (ber-ril). _Syn._ AQUAMARINE' (rene); A'QUA-MARI'NA, BERYL'LUS, L.; AIGUE-MARINE, BeRIL, Fr.; BERYLL, &c., Ger.; SMARAGD, It. A beautiful mineral, which, in its richer forms, is cla.s.sed with the gems. It is usually of a green colour of various shades, pa.s.sing into honey-yellow and sky-blue. It is allied in composition to the emerald; but occurs in much larger crystals than that gem, and owes its colour to oxide of iron instead of oxide of chromium. According to Gmelin its composition is--Silica, 687%; alumina, 176%; glucina, 134%; red oxide of iron, 24%. Other (previous) authorities state that it contains fully 14% of glucina, 2% of lime, and 1% of oxide of iron.

The finest beryls come from Dauria on the frontiers of China, from Siberia, and from Brazil. Some of gigantic size have been found in the U.S., at Ackworth and Grantham, New Hamps.h.i.+re, and at Royalston, Ma.s.s. One of these measured 32 22 15 inches, and weighed 2900 _lbs._; another, 12 24 45 inches, and weighed 1076 _lbs._

Apat.i.te or Saxony beryl, chrysolite or pierre d'asperge, coloured fluor-spar, and even natural crystals of phosphate of iron, are often worked up by the lapidaries and pa.s.sed off as beryls, or false beryls, emeralds, topazes, &c. See GEMS, PASTES, &c.