A treatise on chemistry. Vol. III, The chemistry of the hydrocarbons and their derivatives, or, Organic chemistry. Part I / by H.E. Roscoe & C. Schorlemmer.

  • Henry Enfield Roscoe
Date:
1881
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on chemistry. Vol. III, The chemistry of the hydrocarbons and their derivatives, or, Organic chemistry. Part I / by H.E. Roscoe & C. Schorlemmer. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

    214/744 (page 196)
    portions are first distilled over, and these repeatedly recti- fied over quicklime in order to remove as much as possible acetic acid, water, and tarry substances. The wood-spirit thus obtained contains together with methyl alcohol, acetone, allyl alcohol, methyl acetate, hoinologues, and condensation products of acetone, together with oily bodies and other compounds. The pure alcohol is obtained by first heating with caustic soda in order to convert the methyl acetate into alcohol. The disagree- able smelling impurities are then destroyed by a weak oxidising agent, and the product subjected to a systematic fractional dis- tillation, for which purpose an arrangement is used similar to that employed in the rectification of common alcohol.' The pro- duct obtained in this way, freed as much as possible from acetons and allyl alcohol, constitutes the wood-spirit of commerce. Methyl alcohol is now largely obtained as a by-product in the beetroot sugar industry. In this industry, as in the manu- facture of cane-sugar, large quantities of molasses or treacle remain behind after the whole of the crystallisable sugar has been withdrawn. These molasses are invariably employed to yield ordinary alcohol by fermentation. Now the juice of the beet as well as that of cane-sugar contains, in addition to the sugar, large quantities of extractive and nitrogenous matter, together with considerable quantities of potash salts. In some sugar-producing localities the Avaste liquor or spent-wash from the stills, termed vinasse in French, is thrown away; but in France it has long been the custom of the distiller to eva- porate these liquids to dryness and to calcine the mass in a reverberatory furnace, thus destroying the whole of the organic matter, but recovering thp alkaline salts of the beetroot. In this way 2,000 tons of carbonate of potash are annually pro- duced in the French distilleries. For more than thirty years the idea has been entertained of collecting the ammonia Avater, tar, gas, and oils, given off when this organic matter is calcined; but the practical realisation of the project has only quite re- cently been accomplished, and a most unexpected new field of chemical industry thus opened out through the persevering and sagacious labours of M. Camille Vincent- of Paris. In this process the spent-wash, after evaporation, is submitted to dry distillation. The distillate consists of a complex mixture of ' her. Entiv. Chcm. Ltd. ii. 277. = Compl. Rend. Ixxxiv. 214; Bull. Soc. Chim. [2], xxvii. US; Expos. Univ. 1878, Prod. Chiiii. groupo fl, classc 47.