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.

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    manufacture to be able to determine the quality of the com- mercial product by a simple method. If the substance should only contain water the matter is easy enough, for mixtures of methyl alcohol and of ethyl alcohol with water exhibit, as Deville ^ has proved, almost the same specific gravity for equal percentage mixtures, and hence tables made for the purpose of obtaining the strength of dilute spirit of wine may be employed for wood- spirit. Dupre ^ has also determined the specific gravity of dilute aqueous solutions of wood-spirit of various strengths. More commonly, however, acetone and other ketones are present, as well as water, in common wood-spirit, and this lowers the value of the commercial article, not only by dilution, but also because their presence acts prejudicially on the colour. For the purpose of analysing commercial wood-spirit it is usual to prepare methyl iodide from it, and determine from the quantity of this com- jDOund obtained, the value of the methyl alcohol. This method, first proposed by Krell,^ has been worked out by Kramer and Grodzki,* as well as by Bardy and Bordet.^ METHYL OXIDE OR DI-METHYL ETHER, (CHJ.O. 131 This compound was first prepared in 1835 by Dumas and Peligot ^ by heating the alcohol with sulphuric acid, and termed by them hydrate of methylene. Ebelmenafterwards showed that boron trioxide may be employed instead of sulphuric acid. It was then supposed that methyl oxide was formed by the withdrawal of the elements of water from the alcohol. This, however, is not the case, as will be afterwards explained (see Etherification, under Ethyl Ether ). In order to prepare this compound, a mixture of thirteen parts of methyl alcohol and twenty of sulphuric acid is gently heated to a temperature of 140° in a flask provided with a reversed condenser. The gas which comes oif is washed through caustic soda in order to remove sulphur dioxide and carbonic acid, and then passed into sulphuric acid, which absorbs 600 times its own volume. It appears that in this case the compound 1-1,80, -f- (CHg).,© or SO(OH)2(OCH3), is > Ann..Chim..Phiis. [3], v. 139. = Proc. Ron. Soc., x.x. 336. a Bcr. Dcidsch. C'hcm. Oes. 1873, 1310. Ihid. 1874, 1493. » fiiilL Soc. Chim. xxxii. 4. Ann. CIdm. Pinjs. [2], Iviii. 19. Ibid. [3], xvi. 138.