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.

    86/744 (page 68)
    i'lG. 27 relation between the carbon dioxide and nitrogen in this gaseous mixture, the tubes are brought one after the other into a cylinder filled with mercury (Fig, 27), and fixed in such a position that the level of the mercury inside and outside the tube is the same. The volume of the s:aseous mixture is then read off, a small quantity of caustic potash solution blown into the tube by means of the pipette (Fig. 28), and after this has been moved slowly up and down in the tube, the whole of the carbon dioxide is absorbed. As soon as this is effected, the level of the mercury inside and outside is again equalised, and the volume of the nitrogen read off, and thus the relation between it and the carbon dioxide ascertained. The first tube may contain a small quantity of air; the later ones, on the other hand, ought, if the experiment has been properly conducted, to yield identical results. If the amount of carbon contained in the substance has been previously determined by combustion-analysis, it is easy to ascertain the absolute amount of nitrogen from the relative volumes of the carbon dioxide and nitrogen. This method of Liebig's for the relative determination of nitrogen is simply and easily carried out, but only yields, as he himself remarks, accurate results when the substance does not contain more than four atoms of carbon to one of nitrogen. Moreover, it possesses the disadvantage common to the other relative methods,^ that the determination of the nitrogen is entirely dependent on that of the carbon. 53 Bimsen's Bclativc Metlwd. Bunsen - has proposed another method of nitrogen determination especially valuable for the ^ Maroliand, Joimi. Pi: C'hcm. xli. 177; Gottlieb, Ann. Chem. Pharm. Ixxviii. 241 ; Simpson, ibid. xcv. G3. - Jfandwbrlrrbnch. .Sup])!. 200,