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.

    88/320 (page 68)
    In these mixtures also an increase of density along with diminu- tion of rotatory power could be detected by keeping. After standing for three days, the following results were obtained : Mixture X. i = 0-87630 . = 63-987“ M = 36-847“ (when fresh 37-148“ . IV. <7=0-93840 « = 39-859“ [a] = 38-034“ (when fresh 38 427 ). ’ By reason of this liability to change under the influence of oxidation, oil of turpentine is not altogether a suitable substance for experiments of the above kind, and inattention to this point at the outset entailed the necessity of repeating several of our expenmen s. Fiff. 15. As the observations show, the specific rotation of the oil of turpentine rises with the addition of increasing quantities q of all three solvents, the graphic representations taking the form of curves, of which that for acetic acid appears steepest, that for benzene less so, and for alcohol least (see Fig. 15). Although the curvature in each case is slight, the deviation from a straight line is too great to admit of application of the formula [a] = A + B q. _ . If taking this equation, we proceed to determine the constant A. from two mixtures, values will be obtained, which will always be less