Handbook of the polariscope and its pracitcal applications / adapted from the German editon of H. Landolt, by D.C. Robb and V.H. Veley.

  • Hans Heinrich Landolt
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: Handbook of the polariscope and its pracitcal applications / adapted from the German editon of H. Landolt, by D.C. Robb and V.H. Veley. Source: Wellcome Collection.

    91/320 (page 71)
    The angles of rotation obtained were: Number of Mixture. Instrument. Tempera- ture. a for L = 219-90. [a]. [a] Mean. ■ i Wild Mitscherlich 22-5° 22-0° 20-416° 20-426° 14-492° 14-499° 14-496° 1 Wild Mitscherlich 22-0° 22-0° 13-096° 13-059° 14-809° 14-767° oo CO o III. | Wild Mitscherlich 24-0° 21-5° 6-021° 6-068° 15-036° 15-153° 15-095° Here also the specific rotation undergoes a slight increase with increasing dilution. The graphic representation (Fig. 16) shows that Fig. 16. the three points lie almost exactly in a straight line. Introducing mean value of [a] into the formula [a] — A + B q, we obtain— 1. Calculated from mixtures I. and II. A — 14T89 B = + 0-011415 2. „ „ II. „ III. = 14T50 = + 0-012150 3. „ I. „ III. = 14-179 = + 0-011780 The values here obtained for A agree very closely with the directly observed specific rotation of the oil, = 14*147°. Taking the mean of the above values for A and B, respectively, [a]D = 14*173 + 0*11782 q, which, of course, corresponds closely with the observations. We have—