The specific rotation is increased considerably by the addition of boracic acid. On the other hand, mineral as well as organic acids diminish it, and may even convert it into dextro-rotation. Water 466). p 23.506. t = 2 = = 22. [a]; Antimon-ammonium malate, N H1. Sb O. C4 H4 05. 4 p = 6.845. t = 17. [a]: = +115.47 Pasteur (A. C. P. [3] 31, 85). Amides of malic and tartaric acids. Pasteur, (A. C. P. [3] 38, Glutamic acid, C, H, NO4. Dextro-rotatory. Dilute nitric acid. p 5:45. t 18. [a]D == 34.7. Ritthausen (Journ. für prakt. Chem. [1] 107, 238). 7 Aspartic acid, C4 H, NO4. Dextro-rotatory in acid solutions; lævo-rotatory in alkaline solutions. Soda solution containing 4.84 per cent. Na, O. p = 9.99. (a) Ritthausen's preparation from legumin (Journ. für prakt. Chem. [1] 107, 227). (b) Pasteur's preparation from asparagin (A. C. P. [3] 31, 78). Asparagin, CH, N2 Og. Dextro-rotatory in acid solutions; lævo-rotatory in alkaline. § 116. Terpenes, C10 H16. I. Dextro-rotatory Oil of Turpentine, Australene. [The latter name is applied to the preparation obtained by distillation after neutralization by soda solution.] (a) From Pinus australis and P. Tueda. American or so-called English oil of turpentine. aj [a]; = 13.5 (crude); 14.6 (rectified). Luboldt. = 18.6. Guibourt and Bouchardat. [a]D = 14 15 at 20°. d = 0.9108. Landolt (§ 31, p. 70). Wiedemann (Pogg. Ann. 82, 222) obtained the following angles of rotation for different rays:— Australene. Distilled at 100° with reduced pressure. Portion I. = 24.3. Portion II. [a]; Berthelot (A. C. P. [3] 40, 5). [a]; = 21.4. (Boiling-point, 161°.) (b) From Pinus sylvestris and P. Abies. Russian or so-called German oil of turpentine. Australene from Pinus sylvestris, [a] = 32·4. [a]; D 32.4. [a];= 40.3 with t = 24.5°, (ap = 277, d = 0·8547. Boiling-point, 1555 to 156·5). Flawitzky (D. C. G. 1878, 1846). Australene from Swedish wood-tar of Pinus sylvestris, [a] = 36·3 (d = 0·8631 at 16°. Boiling-point, 156.5 to 157-5.) Atterberg (D. C. G. 1877, 1203). II. Lævo-rotatory turpentine oil. tine. and distilled.) Terebenthene. (Neutralized (a) From Pinus Pinaster (P. maritima). French oil of turpen Commercial oils, a; = 18.2, Luboldt; a = = 31.1, Gladstone; a 35-4 to 36-5, Berthelot; 35-6, Gladstone; 36.5, Gernez; 40·0, Biot; 42-2, Mayer; 43·0, Deville; 43.4, Soubeiran and Capitaine; 455, Buignet. For different rays, Wiedemann (A. P. 82, 222) found: Terebenthene. [a]; = 42.3. G 55.9 (Distilled with reduced pressure, at temperatures between 80° and 100°. Boiling-point, 161°.) Berthelot (A. C. P. [3] 40, 5). [a] = - 37.01 at 20° (d = 0.8629 at 20°. Boiling-point, 161°). Landolt (§ 30, p. 66). [a]D 40.30 (d = v.8685 at 10°. Boiling-point, 156°). Riban (A. C. P. [5] 6, 15). = Iso-terebenthene. Obtained by exposing terebenthene for two hours to a temperature of 300°. [a]D=9-45 (d = 0.8431 at 20°. Boiling-point, 175°). Riban (A. P. C. [5] 6, 218). [a]; (b) From P. Larix. Venetian oil of turpentine. = - 98.8. Rectified: 107 6. Flückiger, Berthelot (J. B. 1855, 643). 2. From young shoots of Pinus pumilio.1 [a]; = 116, 328). By exposure to the air, turpentine oils experience a decrease of rotatory power by oxidation (§ 30), whence probably these discrepancies in the data. When distilled, the unaltered and more highly rotatory portions are carried over first. For the alterations of the rotatory power of oil of turpentine at temperatures above boiling-point, see § 16, p. 35. For information on the rotatory properties of the numerous derivatives of oil of turpentine, as they have been investigated by Deville (A. C. P. [2] 75, 37) and Berthelot (A. C. P. [3] 38, 38; 39, 10; 40, 5), reference must be made to the original memoirs. In the case of most of the solid substances examined the concentrations of 1 Pinus pumilio is the dwarf pine (Krummholz), a species with recumbent stem found in the Alps and Pyrenees.-D.C.R. the solutions employed have not been recorded. The complete data are given only for : Lævo-rotatory camphene. Terecamphene, C10 H16, obtained by heating terebenthene-chlorhydrate with an alcoholic solution of potash or with stearate of soda. Riban (Bull. soc. chim. 24, 10) found for alcoholic solutions with q = 62 to 90 per cent. alcohol, at a temperature of 13° to 14° : [a]D (53.80 0.03081 q). = ― 8 117. Ethereal Oils. Commercial ethereal oils, being invariably mixtures of substances often of opposite optical powers, exhibit so much diversity in respect of rotation values, that these are of no use as a test of their purity, and special data are accordingly worthless. § 118. Resins. Euphorbone, C15 H24 O (from euphorbia resin). Dextro Podocarpic acid, C17 H22 O3. Dextro-rotatory. Laurel-camphor, C10 H16 O. Dextro-rotatory. For specific rotation in various solvents (§ 36, p. 84). The following others have been obtained :- Arndtsen (A. C. P. [3] 54, 418) has determined the specific rotation in alcoholic solutions for different rays, and with different weight-percentages of alcohol (g). t = 22.9°. The formulæ hold Fused. Patchouli camphor, C15 H26 O. Lævo-rotatory. In Alcohol. [a]D 15 Dextro Camphoric acid, from laurel-camphor, C10 H16 04. rotatory. 10 Salts of dextro-camphoric acid. 21-5. [a]D = 460. Landolt. Solutions in water. = 14.39 0.06 c. [a]D [a]D Na2 C10 H14 04 c = 2 (NH4)2. C10 H14 Oc = 4,, 17. 0.06 c. [a]D = 16.98 +0.13 c. Landolt. Methyl-camphoric acid, CH3. C10 H15 04. Dextro-rotatory. Alcohol. p = 143.04. t = 19.3. [a]; = 514. Loir (A. C. P. [3] 38, 485). For the rotatory power of other camphors and their derivatives no sufficient data exist. 0.873 at 15°. a, for 1 decimetre = 15.6). Schiff (L. A. 166, 94). = 0.846 ,, 12.5°). Alcohol reduces specific rotation; ether, benzene, and oil have no effect. Petit (D. C. G. 1877, 896). Nicotine, C10 H14 N2. Lævo-rotatory. (See § 32, p. 72.) CINCHONA ALKALOIDS. Besides those already given, §§ 103, 104, the following data have been further recorded, mostly by Hesse.1 1 Numerous earlier observations on the rotatory powers of alkaloids were made by Bouchardat (Ann. chim phys. [3] 9, 213), Bouchardat and Boudet (Journ. de Pharm. et de Chim. [3] 23, 288), Buignet (Journ. de Pharm. et de Chim. [3] 40, 268), De Vrij and Alluard (Compt. rend. 59, 201). These data are for Biot's red ray; but they are not now of much use, as the nature of solvent employed is scarcely ever recorded with sufficient exactitude. |