194 ODOROGRAPHIA. 



acid passes over at 185^ C, and may be further purified by re- 

 crystallisation from ether.* 



Angelic acid is difficultly soluble in cold, but readily soluble in 

 hot water, and crystallises in long monoclinic prisms which have 

 an aromatic odour and melt at 45^-46^ C. It boils at 185^ C, and 

 when boiled for some time or when heated with sulphuric acid to 

 100° C. is converted into Tiglic acid, with which it is geometrically 

 isomeric ; both having the same constitutional formula. Tiglic 

 acid is found along with angelic acid in Eoman oil of cumin. This 

 remarkable instance of geometrical isomerism has been investigated 

 by Professor Wislicenus of Leipzig and Professor Pittig of Stras- 

 burgh.-j- 



Toddalia. 



Toddalia. An essential oil, w^hich is considered to resemble 

 in odour a mixture of Basilicum and Lemon grass, is distilled from 

 the leaves of the Toddalia aculeata Pers.iJ Syn. FaiUlinia Asiatica, 

 Lin., Spec. 524 ; Scojjolea acideata Smith, a rutaceous shrub very 

 widely dispersed through Asia and extending as far south as 

 Mauritius. It is a shrub of moderate size, with weak or llexnose 

 branches usually armed with small recurved prickles, and bearing 

 trifoliolate leaves composed of oblong or oval-oblong leaflets, the 

 leafstalks and also the midribs of the leaflets being generally 

 prickly. On the Malabar Coast the plant is called Kaka-Toddali. 

 On the Xilgiri Hills it is locally known as " Wild orange tree." 

 Its flowers are white, and, being very strongly scented, could 

 doubtless be utilised in perfumery. 



Three varieties of the shrub are known, viz. : — 



Var a, acanthophylla (D. C. Prod., ii., p. 83), racemes shorter 

 than the leaves ; leaves prickly ; leaflets ovate-lanceolate. 

 Xative of Malabar. Eheede Mai., v., t. 41. 

 Var /3, nitida (Lam. ill., t. 139, f. 1), racemes longer than the 

 leaves ; leaflets ovate, unarmed. Native of Ceylon. 

 Burm. ZeyL, p. 28, t. 24. 

 Var y, riihricaidis (Willd. in Eosmer et Schultes Systema 

 Yegetabilium, v.. p. 323) branches pubescent, leaves 



* Ann. Chem. Pharm., ccl., p. 242, 



■f Ibid, cclxxii., p. 99. 



X Persoon Synopsis Plantarum, p. 249. 



