glycerin, glycerine

[Greek glykeros, glykys sweet; -in, -ine.] 1. Chem. & Comm.: A triatomic alcohol of the fatty series, more properly called glycerol (q. v.), C3H8O3, or CH2(OH)-CH(OH)CH2(OH). Glycerin was discovered in 1778 by Scheele, who obtained it in the preparation of lead-plaster by saponifying lard with oxide of lead. Glycerin occurs in most natural animal and vegetable fats in combination with fatty acids, from which it can be obtained by saponifying with alkalies. (PREPARATION OF SOAP.) It is also formed during the alcoholic fermentation of sugar. Pure glycerin is obtained by heating neutral fats in a still, with a condensing apparatus, and pa ing steam in small jets through the melted fat, the temperature being kept below 600° F., and above 550° F.; the fat acids separate out in the receivers from the glycerin and water; the glycerin is then concentrated by evaporation. Glycerin is a thick, colorle , inodorous, neutral syrup, which sin, as; expect, Xenophon, exist. ph = f. heated with sulphuric acid and manganese dioxide glycocine is decomposed into hydrocyanic acid, CH2, Chem.: C3H6O2. or O by di olving glycidic acetate in ether, adding caus- tic soda, the solution being cooled with ice. Glycide is a liquid boiling at 163°. It is soluble in water, alcohol, and ether; heated with water it is con- verted into glycerin; by the action of dilute nitric acid it is converted into mono-nitroglycerin; it reduces ammoniacal solution of silver salts at has a very sweet taste; it mixes with water in all proportions, is soluble in alcohol and in chloroform, but insoluble in ether. It can be obtained by freez- ing, in deliquescent rhombic crystals, which melt at 17°. Glycerin boils at 290°; it is very hygroscopic; heated to 150° it burns with a bluish flame. Glyc- erin di olves iodine and many metallic oxides and salts, also salts of the alkaloids. The specific gravity of glycerin is 126 at 15°, compared with water at 4. Glycerin distilled with phosphorous pent a chloride, P2Cl5, yields acrolein. By the action of a mixture of equal parts of concentrated nitric acid and sulphuric acid, it is converted into nitro- glycerin, CH2O(NO2·)·CHO(NO2) CH2O(NO2) (q. v.). Glycerin is used for preserving fruits, .; also as a solvent for various salts, and in preparing copying-ink; also as a lubricator for machinery and clockwork, and is placed over water in gas- meters to prevent freezing, and is used for filling floating compa es. It is employed in the form of nitroglycerin in the preparation dynamitend with soap form glycerin soap, which tends to soften the skin. Glycerin is often used to O IMG:content-0553.png:[blocks in formation] glyç-1-nē, s. [Gr. glykys = sweet, because the leaves and roots of some species are sweet.] Bot .: The typical genus of the sub-tribe Glyci- nese (q.v.), the species, all but one of which are decumbent if not even twining, have alternate leaves with axillary racemes or fascicles of yellow flowers. Locality, the warmer parts of the Old World. Glycine soja , the erect species alluded to, is cultivated in the East Indies for its beans. From these the Japanese make a sauce called sooja or soy. gly-çin'-ě-æ, s. pl . [Lat. glycine , and fem. pl. adj. suff.-eœ.] Bot.: A sub-tribe of papilionaceous plants, tribe Phaseoleӕ. gly-co-, pref . [Gr. glykys =sweet.] Sweet. gly-co-chō-lāte, s. [Eng. glycochol ( ic ); -ate .] Chem.: A salt of glycocholic-acid (q. v.). gly cổ-chō-lic, a . [Eng., ., glyco (gen), and cholic (q. v.).) (For def. see compound.) glycocholic-acid, s . IMG:content-0554.png:[blocks in formation] sulphuric acid, a red to a violet color is produced, Glycocholic acid forms salts which are called Glycocholates; the glycocholates of the alkalies and earth metals are soluble in water and in alcohol. Glycocholate of sodium is precipitated from its alcoholic solution by ether; acetate of lead gives a precipitate which is soluble in alcohol. Chem.: Glycocine, glycine, glycocol, amido-acetic acid, glycollamic acid, amido-glycollic acid. obtained by boiling gelatin with baryta, neutral- CHNOOCH(NH) COOH. Glycocine can be izing with sulphuric acid, evaporating and extract- ing with alcohol; by boiling one part of hippuric acid with four parts of fuming HCl, filtered when cold from the benzoic acid, evaporating to expel the exce of HCl, washing the residue with ammonia, then with absolute alcohol; by pa ing cyanogen gas into a boiling concentrated solution of hydri- dxt IMG:content-0555.png:[blocks in formation] ing glycollic acid, glyoxalic acid, and oxalic acid. Heated to 250° with solid caustic potash, it yields pota ium oxalate, and gives off hydrogen, 2KOH+C2H6O2=K2C2O4+SH. Heated with zinc chloride, ZnCl2, it yields aldehyde, an atom of water being eliminated; with PCl5 it forms ethene dichlo- ride, C2H4Cl2; by the action of hydriodic acid, HI, it is reduced to ethyl iodide, C2H3I. Metallic sodium can replace either one or two atoms of hydrogen in the hydroxyl radicals, forming sodium ethenate, cH2OH cH2ONa CH2ONA CHOONa and disodium die then ate, CH2ONa. Glycol di olves KHO and Ca(OH)2. bonic ether in an alcoholic solution, CN COOC2H5+ 4H =H2O+CH2NH2COOH+C2H5OH; by heating bromacetic acid with ammonia; also by heating to 60° dry ammonium carbonate with mono chloracetic acid. It has a sweet taste, and melts at 170°; at higher temperatures it is decomposed. It gives a deep red color with ferric chlorides, which is de- dibromide into diacetate, by means of an alcoholic solution of pota ium acetate, and decomposing the diacetate by caustic potash; also obtained by combining an olefine with hypochlorous acid CIOH, and acting on the chlorhydrin thus obtained c2HCI +AgOH = AgCl+ cHOH stroyed by acids, but restored by ammonia; with by moist silver oxide, J phenol and hypochlorite of sodium it gives a beau- CH2OH tiful blue color. Glycocine forms crystalline com- | pounds with acids, also salts with bases. Glycocine CH2OH The American Dictionary and Cyclopedia IMG:content-0557.png:[blocks in formation] CH2OH The amide of gly. Chem.: C2H5NO2, or CO-N collic acid. Obtained by heating ammonium tar tronate till no more CO2 is given off, and recrystallizing from water; also by the action of ammonia on ethyl glycol late. Glycol lam ide is soluble in water, and slightly soluble in alcohol. It melts at 120°. By the action of alkalis or dilute acids it is converted into ammonia and glycollic acid.