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.

    86/320 (page 66)
    The following abbreviations have been used:— p, percentage of active substance in 100 parts by weight of solution. q inactive ,, » » ” d, specific gravity of the solution at 20° Cent., that of water at 4° being taken as unity. eLdp, the concentration, i.e., the number of grammes of active substance in 100. cubic centimetres of solution. X, the length of tube in millimetres. a, observed angle of deviation of rayi), at a temperature of 20° Cent., expressed in degrees and decimals (circular measure). rai = “* —, the specific rotation for ray D, at a temperature of 20° Cent. L JD L . c I. Left-handed Oil of Turpentine. § 30. Two kilogrammes of Bordeaux oil, after standing for several weeks over calcium chloride, were submitted to distillation. Nearly the whole came over between 160° and 162° Cent. Height of barometer = 737 millimetres. Specific gravity O’86290. The rotation was observed with a Wild’s instrument, having two bath-tubes of different lengths. Expt. L. a. Mm I. 99*92 31*905° 37*004°, II. 219*79 70*204° 37*016°. Mean : [a]D = 37*010°. It should be remembered that when oil of turpentine is kept in vessels containing air, it undergoes a process of oxidation, whereby the specific gravity of the oil is increased and the rotatory power diminished. A portion of the above oil, after standing thus for four weeks, gave a specific gravity of 0*86779, and with a 219*79 millimetre tube showed a deviation of 68*144, whence [a]D = 35*728°. (a.) Mixtures with Alcohol. Alcohol, as nearly as possible anhydrous, with a specific gravity 0*7957, was used. The following mixtures were examined with Wild’s polariscope :— Number of Mixture. Oil of Turpen- tine P• Alcobol ! d. c. a for L = 219-79. [«]»■ I. 90-0530 9-9470 0-85558 77-0474 62-716° 37-035° II. 69-9416 30-0584 0-83923 58-6971 48 052° 37-247° III. 49-9658 50-0342 0-82542 41-2428 34-036° 37*548° IV. 29-9715 70-0285 0-81273 24-3588 20-293° 37*904° V. 10-0078 89-9922 0-80108 8-0170 6-782° 38-486°