- 64 - 



When boiled with dilute sulphuric acid, the erythritol gave off 

 water and was converted into thymol and carvacrol. B. p. 232 to 

 236 , d i5 o 0,9841, «d+°j n D20° 1*52320. The nitroso- compound 

 was not suitable for the identification of the phenols, for it was im- 

 possible to obtain bodies of a uniform melting point. The urethanes 

 were therefore used for identification purposes, their different solu- 

 bilitys in petroleum ether making separation possible. The phenylies 

 urethane, m. p. 13 6°, sparingly soluble in petroleum ether, was found 

 to be identical with carvacrol phenyl urethane. The portion which 

 dissolved readily in petroleum ether was thymol phenylurethane, 

 m. p. 103 to 104 . 



Upon oxidising the erythritol with chromic acid we obtained a 

 mixture of oily substances which gave no reaction with semicarbazide. 

 Oxidation with permanganate (6 g. erythritol dissolved in 400 cc. water, 

 12 g. potassium hydroxide, 21,5 g. of potassium permanganate and 

 500 g. ice) produced principally two solid, non-volatile acids, of which 

 one, m. p. 97 to 98 , was identical with oxalic acid. Of the second 

 acid, m.p. 147 to 149 , only the very smallest quantity had been obtained. 

 When heated in a test tube it gave off carbon dioxide gas. It may 

 possibly be identical with /^-propyl tartronic acid, which has been prepared 

 by Bruner, and of which the melting point is stated to be about 149 . 



When shaken with alkaline bromine liquor the erythritol yielded a 

 highly volatile brominated body, crystallising out from alcohol in large 

 flakes, m. p. 93 to 94 . All these reactions, which are illustrated by 

 formulae in the Wallach Jubilee-publication, agree with the erythritol 

 possessing the constitution of a 1,2,4, 5-tetrahydroxy hexahydrocymene. 

 Thus, the identification of ^-terpinene is made quite simple, even 

 small quantities being readily traceable. 



Bisabolene. 

 The sesquiterpene fractions of lemon oil were found to possess 

 the following properties: — b. p. no to 130 (7 to 8 mm.), diso 0,9108, 

 «p — 28 14'. One fraction, m. p. no to 112 (4 mm.), di 5 o 0,8813, 

 a D — 4i°3i', n D20° I >49 OI 5> agreed with the sesquiterpene which had 

 already been isolated by us previously. By passing hydrochloric acid 

 into the ethereal solution a tri-hydrochloride, crystallising in flakes, was 

 obtained. This body melted at 79 to 8o° (79,5°), «d ± o in a 

 5 per cent, chloroform solution. The hydrochloride was converted 

 according to Wallaces method, with sodium acetate and glacial acetic 

 acid, into the hydrocarbon: — b. p. 261 to 262 (75 1 mm.), di 5 o 0,8759, 



«D ± O, n D20 o 1,4901. 



This sesquiterpene is identical with bisabolene, which was discovered 

 by Tucholka x ) in the oil of Bisabol Myrrh, and also identified by him 



>) Arch, der Pharm. 235 (1897), 289; Report October 1897, 36. 



