Origin. The oil obtained by pressure from the fruits of the laurel tree consists of a mixture of fatty oil with about 2,5 p.c. of volatile oil6). It finds application in the drug stores under the designation Oleum Lauri expressum. The volatile oil appears to be of no practical value, hence it has been prepared only occasionally for scientific purposes. The yield, computed from the berries, amounts to about 1 p.c.
l) Liebig's Annalen 252 (1889), 96.
2) H.Haensel, Chem. Zentralbl. 1908, I. 1837.
3) Report of Schimmel & Co. April 1906, 43.
4) H. Thorns and B. Molle, Arch, der Pharm. 242 (1904), 161; Arbeiten aus dem pharmazeut. Institut Berlin 1 (1903), 95.
5) Report of Schimmel & Co. April 1899, 29.
) H. Matthes and H.Sander, Arch, der Pharm. 246 (1908), 165.
Properties. The oil of the berries is somewhat more viscid and its odor is a little less delicate than that of the leaves. Because of its lauric acid content it occasionally congeals at temperatures above 0°. d15o0,915 to 0,935. The angle of rotation, determined for a single oil was - 14° 10'. The same oil was insoluble in 80 p.c. alcohol, but dissolved in 1/2 vol or more of 90 p.c. alcohol.
Composition1). The lowest fractions of the fruit oil contain the same constituents2) as does the leaf oil, viz., but very little a-pinene (m. p. of nitrol benzylamine 122 to 123°) and much cineol (cineol hydrobromide). The supposed laurene3) has revealed itself as a mixture of these two substances. The portion of the oil which boils at about 250° (d 0,925; aD - 7,2°) is of the composition C15H24, hence a sesquiterpene4).
Another constituent of the fruit oil, the amount of which varies with the length of the distillation, is lauric acid. It can be withdrawn from the oil by means of caustic alkali; when pure, it melts at 43°5). In addition to these substances, the laurel berry oil contains ketones and alcohols which form solid compounds with sodium. Regenerated with water, they constitute a viscid oil which under 20 mm. pressure distills over between 71 and 184°.
The statements made by Gladstone6) that eugenol is contained in the oil of the laurel berries was not confirmed by Bias and Muller. Although Gladstone designates his oil as a bay oil from the berries of Laurus nobilis, it is not impossible that his oil was, in all probability, a bay oil which consisted largely of eugenol.7)
1) The earliest investigations were conducted by Bonastre (Journ. de Pharm. 10 , 36 and 11 , 3; Repert. f. d. Pharm. I. 17 , 190) and by Brandes (Arch, der Pharm. 72 , 160).
2) Wallach, Liebig's Annalen 252 (1889), 97. - J. W. Bruhl and F. Muller, Berl. Berichte 25 (1892), 547.
3) Bruhl, Berl. Berichte 21 (1888), 157.
4) C. Bias, Liebig's Annalen 134 (1865), 1. 5) Bruhl and Muller, loc. cit.
6) Journ. chem. Soc. II. 2 (1864), 1; Jahresb. f. Chem. 1863, 545.
7) As becomes apparent from a paper by Ashton (Chemist and Druggist, July 2, 1892) it is evident that in England the terms bay oil and laurel oil are frequently confounded.