28 



HYDROCARBONS 



[4 A-6. 



SYNTHETICAL PEOCESS. 



[A.] From myristic acid [Vol. II] 

 through myristone ^by distilling the 

 calcium or barium salt (Overbeck, 

 Pogg. Ann. 86, 591; Ann. 84, 290; 

 Krafft, Ber. 15, 1713); the dichloride 

 by distilling with phosphorus penta- 

 chloride, and reduction of the dichloride 

 by heating with aqueous hydriodic acid 

 and phosphorus (Krafft, loc. cit.}. 



NOTE : A heptacosane may occur in ne"roli 

 oil (E. and H. Erdmann, Ber. 32, 1214), but the 

 constitution of this hydrocarbon is at present 

 unknown. 



5. Normal Hentriacontane. 

 CH 3 [CHJ 29 . CH 3 



NATUEAL SOUECES. 



Occurs with the preceding in bees- 

 wax (Schwalb, loc. cit.) and tobacco leaf 

 (Thorpe and Holmes, loc. cit.). 



SYNTHETICAL PEOCESS. 



[A.] From palmitic acid [Vol. II] 

 through palmitone by distilling the 

 barium salt (Piria, Ann. 82, 249) ; the 

 dichloride as above, and reduction of 

 latter as before (Krafft, loc. cit. 1714). 



6. Cymene; 



Faraisopropyltoluene ; 



Paramethylisopropylbenzene ; 



l-Methyl-4-Metlioeth.ylbenzeiie. 

 CH 3 



CH S . CH . CH S 



NATUEAL SOUECES. 



In Roman cumin oil from the seeds 

 of Cuminum cyminum (Gerhardt and 

 Cahours, Ann. 38, 70; 101 ; 345); in 

 oil from the seeds of water- hemlock, 

 Cicuta virosa (Trapp, Journ. pr. Ch. 74, 



428; Arch. Pharm. 231, 212; Ann. 

 108, 386) ; in oil of pepperwort, Satureia 

 hortensis (Jahns, Ber. 15, 816), and of 

 Satureia thymbra (SchimmeFs Ber. Oct. 

 1889). 



Cymene occurs in oil of true bishop's 

 weed, Ptychotis ajowdn (Haines, Journ. 

 Ch. Soc. 8, 28; Miiller, Ber. 2, 

 130; Landolph, Ber. 6, 936); in oil 

 of thyme from Tkymus vulgar is and 

 T. serpyllum (Lallemand, Journ. Pharm. 

 24, 274 ; Comp. Rend. 37, 498 ; Ann. 

 102, 119; Febve, Comp. Rend. 92, 

 1290); in oil of wild bergamot from 

 Monarda fistulosa (Kremers, Pharm. 

 Rund. 13, 207 ; Melzner and Kremers, 

 Pharm. Rev. 14, 198); and in oil of 

 American horsemint from Monarda 

 punctata (Kremers and Hendricks, 

 Pharm. Arch. 2, 73 ; Schumann and 

 Kremers, Pharm. Rev. 14, 223). 



According to Faust and Homeyer 

 (Ber. 7, 1429) cymene occurs in the oil 

 of Eucalyptus globulus, but according to 

 Gildemeister and Hoffmann (p. 691) 

 the oil investigated by these chemists 

 could not have been from that species. 

 Cymene occurs in oil of Eucalyptus 

 kcemastoma (Gildemeister and Hoff- 

 mann, p. 161), in oil of Thymus 

 capitatus from S. Spain (SchimmePs 

 Ber. Oct. 1889), in oil of Trieste and 

 Smyrna origanum from Origanum Jiirtum 

 and 0. smyrn&um (Jahns, Arch. Pharm. 

 215, I; Gildemeister, Ibid. 231, 182), 

 and in Ceylon oil of cinnamon (Schim- 

 mePs Ber. April, 1902; Walbaum and 

 Hiithig, Journ. pr. Ch. [2] 66, 47). 



According to Tardy (pull. Soc. [3] 

 17, 580 ; 660) cymene is contained in 

 the oil of French bitter-fennel, but it 

 more probably resulted from the action 

 of hydrogen chloride on some other 

 constituent of the oil (Gildemeister 

 and Hoffmann, p. 740). According to 

 Klason the oil extracted from pine- 

 wood during the sulphite cellulose pro- 

 cess is cymene (Bied. Centr. 27, 137 ; 

 Ber. 33, 2343). 



Cymene is contained in the steam 

 distillate from lemon-grass oil from the 

 Indian Andropogon citratus (Dodge, Am. 

 Ch. Journ. 12, 553 ; Stiehl, Journ. pr. 

 Ch. [2] 58, 51). Cascarilla oil from the 

 bark of Croton eluteria contains cymene 



