cask is perforated so as to admit air, and the vinegar trickles out at the bottom. The presence of certain substances, as aromatics, fluid oils, and pyroligneous acid, prevent the conversion of alcohol into vinegar. 4. Cider Vinegar is made in America from refuse cider. 5. Sugar Vinegar, made by exposing for a summer a mixture of 20 lbs. sugar, 16 water, and 24 pints bruised gooseberries, and some yeast and raisins. 6. Pyroligneous Acid, Wood Vinegar, is obtained by distilling the harder kinds of wood, as oak, birch, &c. in iron cylinders, the acetic acid being afforded in largest quantity by the ligneous matter and not by the cellulin. The wood affords from 800 lbs., 160 lbs. of charcoal, 300 vinegar, and 340 of gases. The distillation lasts 8 hours. The acid liquor is separated by gravity from the oils, and is again distilled, and is saturated with lime or soda; the acetate thus formed is finally distilled with sulphuric acid. Wood vinegar retains a small portion of creasote and other oils, which render it valuable for preserving meat and vegetable substances. Acetates are generally soluble in water, with the exception of the acetates of molybdenum and tungsten. Some of them are very important - as the acetate of copper or verdigris; Acetate of alumina, a valuable mordant; acetate of lead, or sugar of lead, used in medicine and the arts; Acetate of ammonia, or spirit of Mindererus, used to promote sweating.

Tests for acetates. - Add to a few drops of perchloride of iron so much water as to form a colourless solution. The addition of an acetate renders it yellow; SO, when added to an acetate evolves the smell of vinegar.

Chloracetic acid C, Cl, O3, colourless needles obtained by the action of Cl upon strong acetic acid in the sun's rays; formed on the same model with acetic acid.

Ethionic and Isethionic acids are obtained by treating alcohol with solid sulphuric acid.

3

3

Acetone, Pyroacetic spirit, Naphtha, C, H, O.- A colourless fluid, with an ethereal odour; sp. grav. 79, of vapour 2·022; obtained by distilling acetate of lead (Beccher and Proust) or acetate of lime, the action being (CaO C, H, O, become CaO CO, and C, H, O) due to the formation of carbonate of lime and acetone. It has been used in the treatment of consumption, but not with any benefit. It is supposed to be analogous to alcohol in its nature, or the hydrous oxide of an organic radical Mesityle (C, H, O). Mesitylene (C H4), obtained by treating acetone with fuming S O3. Chloride of mesityle (C H, Cl), obtained by treating acetone with chloride of phosphorus. When this fluid is distilled with KO it is converted into oxide of mesityle (CÅ HÅ O).

Cacodyle (C, H, As, Kd) a colourless fluid, obtained by distilling chloride of cacodyle with metallic zinc. Oxide of

N

cacodyle, alcarsin, fuming liquor of Cadet (C4 H AsO, or Kd 0), an ethereal, colourless fluid, boiling at 3020, and becoming solid at-9; disagreeable penetrating odour; density of vapour 7.55; obtained by distilling equal weights of acetate of potash or soda and arsenious acid; CO, is given out. It is highly poisonous, and takes fire spontaneously in air. It is formed by subtracting 2 CO, from 2 atoms of acetone and 1 arsenious acid (C H O2 As O, less 2 CO2=C1 H ̧ As O). Cacodylic acid (C, H As O, HO), formed by the slow action of air upon oxide of Kd, when the latter is placed under water; occurs in colourless crystals without smell; unites with alkalies. Chloride of cacodyle (CH, As Cl), colourless fluid, obtained by digesting the oxide with H Cl.

Amyle hydrous oxide of, oil of grain, fuseloil, oil of whisky, potatoe oil (C10 HO HO). This oil comes over in the distillation of the infusion of barley, oats, and potatoes, mixed with alcohol and water, and is purified by washing it with water, and distilling over chloride of calcium. It is a colourless oily fluid, with a peculiar, strong, penetrating odour, perceptible in the chest; burns with a white flame, and is poisonous; hence it should be entirely removed from spirits, otherwise they must be prejudicial. Spec. grav. 812. Boiling point 26910; spec. grav. of vapour 3147; mixes in all proportions with water and alcohol. Chloride of amyle (Ayl Cl). — Colourless fluid, obtained by distilling grain oil, and perchloride of phosphorus. Sulphate of amyle and barytes (Ayl SO, BaO SO3), obtained by boiling the oil with SO3, and saturating with carbonate of barytes: it crystallizes in pearly scales. From the existence of this salt, it was at once concluded that the oil of grain is an alcohol- that is, the hydrous oxide of an organic radical, - and it was found that it forms a series of analogous compounds to those of alcohol. All the organic radicals have a peculiar acid derived from them, Alcohol has acetic acid; formyle, formic acid; and amyle has nalerianic acid (delphinic acid, amylic acid) (C, H, O, HỌ), originally obtained from valerian root, but easily formed from grain oil by distilling it, at 400°, with a mixture of equal parts of hydrate of potash or soda and quicklime; hydrogen is set free, and valerianate of amyle remains in the retort; by distillation with SO, the valerianic acid comes over-a colourless oil swimming on water, sp. grav. 937., of vapour 3 660. It occurs in the berries of the Guelder rose. Amilene (C10 H10), a colourless fluid, is formed by distilling grain oil with anhydrous phosphoric acid. Chlorovalerisic acid (C10 H, Cl, O4), thick fluid, without odour, formed by acting on valerianic acid with chlorine in the dark. The Cl replaces 3 atoms of H. Chlorovalerosic acid (C10 H5 ClO3), produced by Cl acting in sun-light. Chloramilal (C20 H7 Cl, O4) an oil boiling at 356°, formed by saturating hydrate of amyle with Cl.

10

IV. OTHER SECRETIONS OF PLANTS AND ALLIED BODIES.

Additional Organic Radicals mostly derived from the Secretions of

Plants.

Benzoyle Series. The compounds now to be described are all connected with the oil of bitter almonds, a substance much employed for seasoning in cookery; and it is interesting in organic chemistry, as constituting the first body from which the theory of organic radicals was deduced by Liebig. The basis of the series is a hypothetic body, benzoyle (C14H5O2), and is supposed to exist because we can obtain an oxide of such a base (C14H50,0), and a chloride by replacing the oxygen (C14H5OCI). Hydret of Benzoyle, oil of bitter almonds, (C4H6O2 or C14H5O2+Hor BzH), obtained from bitter almonds by distillation. The almonds are bruised and strongly pressed; a yellow oil separates, destitute of smell. The expressed cake is cut into pieces and made into a paste with cold water, and in 24 hours the mixture distilled; a heavy oil collects in the receiver, over which swims water containing hydrocyanic acid (prussic acid), to be separated by redistillation with red oxide of mercury; percyanide of mercury remains in the retort. Characters.Colourless, limpid, smell strong and peculiar, specific gravity 1043; boiling point 3240, soluble in 30 parts of water; mixes with alcohol and ether; not poisonous burns with much light and smoke; passes through ignited tubes without decomposition; exposed to the air it unites with 2 atoms oxygen, and is converted into benzoic acid (C14H604); an alcoholic solution of the oil when heated with KO, yields benzoate of potash and a new oil; Cl and Br convert it into BzCl and Bz Br, hydrochloric and hydrobromic acids being formed. Theory. The formation of the oil depends upon the actions of two bodies existing in the almonds upon each other- amygdalin, and emulsin or synaptase, which are prevented from coming in contact by the fat oil at first expressed; hence, as soon as this oil is removed the reaction occurs. Amygdalin C40N H27011, a substance in pearly scales when crystallized from alcohol or in short needles dissolving readily in water, insoluble in cold alcohol, not acted on by dry chlorine. By NO, resolved into NH3, oil of benzoyle, benzoic acid, formic acid, and CO2; and by KO into amygdalic acid. Amygdalin is procured from the almond cake after expressing the fat oil by boiling with alcohol, of specific gravity 812; the spirit is distilled off by the water bath, the syrupy residue diluted with water, and fermented with yeast to remove the sugar; the liquor is then concentrated to the consistence of syrup and mixed with alcohol of about 812 sp. grav., when the amygdalin falls as a crystalline powder. Emulsin, synaptase, legumin, obtained by making an emulsion of sweet almonds with water, adding ether to take up the oil, and precipitating the clear liquor by alcohol; or by treating the expressed sweet almond cake with cold water, precipitating the albumen by acetic acid, the gum by disacetate of lead, and the synaptase by alcohol. It is a white tasteless powder. It is a remarkable body: in contact with salicine producing grape sugar and saligenine, apparently by force of contact or fermentation; and with amygdalin it forms oil of bitter almonds and prussic acid, at the expense of the amygdalin and some emulsin - C40NH27011 (amygdalin) becoming CNH (hydrocyanic acid), C28H12O4 (2 oil of bitter almonds), and a new body C10H14018, from which, by decomposition, sugar is formed, and perhaps formic acid. In consequence of the production of a definite quantity of prussic acid in this process, it may be employed to prepare this acid as a medicine. Process. Mix 34 grains amygdaline with 66 grains emulsion of sweet almonds, so as to produce 100 grains of a mixture containing 2 grains hydrocyanic acid, ( grain amygdalin, cor.. responding to 1 grain of medicinal acid); the solution of 1 grain of amygdalin in 3 ounces of emulsion of sweet almonds, contains, therefore, 1 grain medicinal acid for every ounce of mixture. Benzoic acid (C14H5O3HO) can be obtained by the oxidation of bitter almond oil, or

by heating gum benzoin in an iron pot or porcelain bason. A cover of filtering paper is pasted over the mouth of the vessel, into which has been introduced powdered benzoin, and over the whole is pasted a paper cap, and heat is applied cautiously for some hours. The acid sublimes through the cover into the cap. Characters. - White pearly plates or 6-sided needles, tasteless; when heated it smells of benzoin; reaction acid; fuses at 2480, and sublimes at 298°; specific gravity of vapour 4:27; dissolves in strong SO3, and is reprecipitated by water; dissolves in 200 cold, 25 boiling water. Benzoate of ammonia, formed by saturating the acid with carbonate of ammonia; crystallizes in feathery needles, and is used to precipitate iron from manganese; it is also introduced into some of the preparations of opium. Formo-benzoic acid C16H7O5, is obtained by dissolving oil of bitter almonds in water, and evaporating with hydrochloric acid; sal-ammoniac being formed, and a yellow crystalline acid body in scales, soluble in alcohol and ether, decomposing by heat into oil of bitter almonds and hydrocyanic acid, of which two substances it consists. Benzoate of bitter almonds (C42 H18 Og), 4-sided prisms, formed by passing Cl through the oil. Hydrobenzamide (C42H18N2), in octohedral crystals, by pouring 20 NH on 1 part of the oil, and digesting at 1100 for 24 hours; it is insoluble in HO9. Amarine (C42H18N2), obtained by boiling the preceding body with KO. Benzostilbine (C31 H11O2), white crystals, by acting on hydrobenzamide with fused potash. When hydrobenzamide is distilled it yields silky needles, Lophin (C46H16N2). By distilling the oil of bitter almonds frequently we obtain benzimide, colourless needles (C29 H11 NO4), and when sulphohydret of ammonia is added to a solution of the oil in alcohol, a starchlike powder falls, which is hydret of sulphobenzoyle (C14H6S2); this, when distilled, gives, first stilbene (C2H12), and afterwards thionessale in needles (C26H9S); chlorine, bromine, and NO5, act upon stilbene by substitution, these bodies replacing hydrogen. If we add to bitter almond oil, containing hydrocyanic acid, an equal volume of falcohol in which caustic potash is dissolved, yellow crystals subside of benzoin (C28H12O4), which is converted by boiling with potash into benzilic acid, and into benzoinamide (white needles) by standing in contact with NH3 for some months; into benzil (C28H10O4), by passing chlorine over it in a fused state; the Cl removes hydrogen without substitution. Hippuric acid (C18 H,NO5HO) is intimately allied to this series since it may be procured in human urine in large quantities by taking benzoic acid internally. It exists, however, in the natural state in human urine, and in that of the cow and horse. It may be obtained by carefully evaporating the urine of the cow, and adding HCI so as to produce a feeble acid reaction. Impure crystals of hippuric acid are deposited, and may be purified by passing Cl through a boiling solution. It is to the presence of a small portion of this acid in a free state that the acidity of urine has been attributed. Action of agents on benzoic acid.— Benzole (C12H6), bicarburet of hydrogen of Faraday, obtained among the oils from condensed oil gas, and by distilling benzoic acid with hydrate of lime (C14H604 and 2 CaO, giving C12H6 and 2(CaO CO2), or passing the vapour of this acid through a red hot gun barrel. A clear colourless ethereal fluid, solidifying at 32°, boiling at 1860. When all the benzole has been distilled, an oil benzone comes over (C13H5O) with naphthaline. Chlorine unites with benzole when they are exposed in a large flask to the sun, and forms chlorobenzole (C12H6C6) in white crystals, melting at 270°, insoluble in water. When this substance is distilled it affords chloroan oily, colourless fluid, boiling at 410°. Nitric acid acts upon benzole by giving out oxygen and hyponitric acid, replacing hydrogen and forming nitro-benzide, C12

benzide, C12, H3 Cl3'

H5
NO1'

may be obtained

a yellow oil, boiling point 4150, specific H4 gravity 1.209, of vapour 4-294. Binitrobenzide, C12 2. NO4' by treating benzole with 'SO, and NO5. If we dissolve nitrobenzide in alcohol, saturate the solution with NH3 and pass a current of SH through the deep red mixture and allow it to stand, sulphur drops; the SH is again passed, HCI added in excess; by evaporation a clear fluid remains, Aniline (C12H,N), obviously produced by the separation of all the oxygen by means of SH, and the place of the oxygen supplied by H from the gas. This substance is likewise obtained from coal-tar, and indigo, and is recognised by giving a

fine violet blue with solutions of chloride of lime. When the binitrobenzide, dissolved in alcohol, is treated with sulphohydret of ammonia, nitraniline, When nitrobenzide is distilled

H6
NOA

N, is obtained in yellow needles.

C12 with KO, crystals come over of azobenzide (C12H5N). Sulphuric acid gives out an atom of oxygen to 1 of H in benzole when in contact with it, and forms an atom of water, while sulphobenzide (C12H5SO2) remains in crystals. By filtering off the acid liquid from this process, saturating with carbonate of barytes, we obtain hyposulphobenzidic acid, C12 H5 SO3, united with barytes,

SO2

and by adding sulphate of copper we obtain the copper salt in crystals. Benzonitrile (C14HN), a clear fluid oil, obtained by distilling benzoate of ammonia. Parabenzoyle (C14H5 O2), obtained, by distilling benzoate of copper, in long white needles.

Salicyle Series. Salicine (C26H18O14), a neutral bitter substance in white needles, is extracted from different species of willow, and used sometimes in medicine as a substitute for quinin, fusing at 2480, dissolving in 5 parts of cold water, in SO, with a blood red colour (rutilin). The fresh bark is boiled in an iron pan with water, and exhausted; the decoction is concentrated; the gum, tannic acid, and extract precipitated by acetate of lead, and filtered; the excess of lead removed from the filtered liquor by SO, and Ba S; filtered, and the salicine crystallized. Saliretin (C14H6O2), a resinous-like body, is obtained by boiling salicine with HCI or SO3. The salicine is decomposed into grape sugar and saliretin. Chlorine in the cold state produces chlorosalicine (C26H17 C1014), a yellow powder, and at 140° a red oil (C26H16Cl2O14). When 1 salicine is distilled with 1 bichromate of potash, 2 SO3, and 20 water, a clear oil comes over, which also exists in meadow sweet (spiræa ulmaria), termed salicylous acid or hydrospiroilic acid (C14H5O4H), supposed to be a compound of salicyle and hydrogen; specific gravity 1173, of vapour 4.276, gives a violet colour with persalts of iron, and forms salicylites. With NH3 it forms salicylimide (C42H18O6N2), yellowish white needles. When mixed with ammoniacal acetate of copper salicilimide of copper (C14H6NO2Cu), in brilliant green plates, forms. Salicylic acid (C14H5OHO) resembling benzoic acid, is obtained by treating salicylous acid by potash. Chlorosalicylic acid (C14H5O4C1), in oblique rhomboids, obtained by passing dry Cl through dry salicylous acid. Chlorosalicylimide (C42H15 Cl3 Ŏ6N2), a yellow mass, formed by passing NH, gas into the previous acid. By NO, salicylous acid is converted into nitrosalicylic acid (C14H5ON), in small prisms, dying the cutis yellow, and forming a blood colour with NH3. Carbolic acid (C12H6O2), an oil resembling creasote, and found also in coal oils, is obtained by distilling salicylic acid with glass powder. Helicine (C26H16O14) crystals obtained by digesting salicine with weak NO5. When salicine is exposed along with emulsin or synaptase to a heat of 104 pearly crystals, separate of saligenin (C14H8O4), forming an indigo blue colour with sesquioxide of iron salts, while grape sugar remains in solution. It is scarcely correct to say even that salicine consists of these two principles any more than it would be to consider sugar as composed of alcohol and CO2. Phloridzin (C42H29O24), silky prisms with a square base, a substance closely allied to salicine, is obtained from the bark of the root of the apple, pear, plum, and cherry trees, by alcohol; specific gravity 143; soluble in 1000 parts of water; loses 4 atoms of water at 2120. Phloretin (C30H15O10), crystalline powder, formed along with grape sugar by boiling phloridzin with any acid except NO, and CrO3. Nitrophloretic acid C30H12015 N brown powder, obtained by acting on phloridzin with NO5. Phloridzein C42H29 O26 N2, a red body, formed by acting on moist phloridzin with NH3. "Cinnamyl Series. - Cinnamyl (C18H7O2) is the hypothetic radical of this series. Oil of cinnamon obtained by distilling the bark of the laurus cinnamomum, is a yellow oil, consisting of CigHg O2; converted, by exposure to the air, and absorption of ogygen into cinnamic acid (C18H7O3HO) in tufted crystals; this substance is also formed by dissolving the balsam of Peru in an alcoholic solution of potash, evaporating, dissolving the potash salt in water, and removing the potash by HCl. This acid unites with 1 atom of base. By acting on cinnamic acid with strong NO5 nitrocinnamic acid (C18H6O3NO4HO), in crystals, is formed. Nitrate of hydrate of cinnamyle