OIL OF PEPPERMINT. 897 



in prismatic needles, has an acid burning taste, is scarcely 

 soluble in water, dissolves easily in alcohol, and may be sub- 

 limed. When hydrated cuminic acid is distilled with 4 parts of 

 caustic barytes, it yields an aromatic colourless liquid, C 18 H 12 , 

 to which the name cumene has been applied ; it boils at 291.2 

 (144 centig.) Cumene is analogous to benzin or benzole; it 

 forms with fuming sulphuric acid sulphocumenic acid, corres- 

 ponding with sulphobenzic acid, of which the barytic salt is 

 crystallizable. With nitric acid it forms nitrocumide, ana- 

 logous to nitrobenzide. 



Cymene has been found to correspond perfectly in density, 

 boiling point, and density of vapour with camp ho g en from cam- 

 phor, and is believed to be identical with it. It also appears 

 to be isomeric with retinylene from the distillation of resin. It 

 forms a sulphocymenic acid. 



Lavender oil, C 15 H 14 O 2 (=3C 5 H 4 + 2HO.) This familiar oil 

 is thin, colourless, of density 0.877- 



Oil of peppermint from Mentha piperita is pale yellow, and 

 lighter than water. It contains a variable proportion of stea- 

 ropten, so much as sometimes to form a solid prismatic crys- 

 talline mass. The composition of the elaopten is C 21 H 10 O 2 ; of 

 the stearopten C 20 H 20 O 9 . Phosphoric acid withdraws two 

 atoms of water from the last, and eliminates a liquid hydro- 

 carbon, which M.Walter has named menthene^C^H^. Dis- 

 tilled with perchloride of phosphorus, the stearopten also gives 

 chloro-menthene, C 20 H 17 C1. Chlorine is absorbed by the stea- 

 ropten, and two different chlorinated compounds formed. By 

 the action of nitric acid a liquid acid compound is produced, 

 C 10 H 9 O 3 . (P. Walter, An. de Chirn. Ixxii. 83.) 



Oil of cedar (solid), C 32 H 26 O 2 , or C 32 H 24 + 2HO. The crude 

 essence as obtained from the cedar wood of Virginia is a soft 

 white crystalline mass, which after being deprived of water by 

 heat becomes solid at 80.6 (27 centig.) Distilled by a sand- 

 pot heat, it comes over between 527 and 572 (275 and 300' cen- 

 tig.), and separates into a crystalline substance and liquid por- 

 tion. The solid essence, purified by pressure and crystalli- 

 zation from alcohol is remarkable for its beauty and lustre, its 

 odour is aromatic and peculiar, suggesting that of a cedar-wood 

 pencil. It fuses at 165.2 (74 centig.), and boils at 539.4 

 (282. centig.) ; it is dissolved very slightly by water, largely by 



2 N N 



