36 ODOROGKAPHIA. 



safrene or uncrystallisable portion of oil drained off from the 

 crystals of safrol. 



According to Dr. Poleck, safrol is an extremely stable compound^ 

 the oxygen not being contained in the molecule, as hydroxyl, but 

 in much closer combination, all his attempts at its reduction being 

 unsuccessful. In the behaviour of safrol towards reagents it 

 presents no analogies with alcohols, ethers, phenols, quinones or 

 other classes of organic compounds.* Dr. Poleck considers that it 

 is probably a methylpropyl benzol, or cymol, in which four atoms 

 of hydrogen of the benzol are substituted by two atoms of oxygen. 



It has been shown by Eijkmannf that by means of perman- 

 ganate of potassium, safrol yi^lii^ piper onylic acid: — 



C, H, ( fj > CH, ) C 



COOH 



therefore may be represented by the formula : — 







Piperononylic acid is obtained Ijy oxidising piperonal (now 

 known in perfumery under the name of heliotropin, series i.,. 

 p. 188):— 



^\ H3 ( Q>CH, ) CHO 



and Poleck \ thinks that he observed piperonal among the products 

 of the treatment of safrol with permanganate of potassium, for the 

 action of this salt on safrol is by no means simple, 4 per cent, of 

 piperonylic acid only having been obtained by him. The discovery 

 of safrol in the oil of the Camphor tree, Cinnamomum campliora^ 

 was made by Messrs. Schimmel and Co., of Leipzig, in 1885, who 

 now separate it out in a state of absolute purity from that oil and 

 to an extent which probably exceeds the whole distillation of 

 crude sassafras oil in the United States. 



Safrol is identical with the body named Shikomol by Eijkmann,§ 

 which is the chief constituent of the volatile oil of the fruit of Illicium 



* Chem. Zeit., 1884, 1453. 



t Recueil des travaux cliimiques des Pays Bas, iv., 1885, p. 32, and 

 " Referate " of the Ber. Deutscli. chera. ges., 1885, p. 281. 

 :: Ber. Deutsche, chem. ges., 1886, p. 1096. 

 § Receuil des Travaux chimiques des Pays Bas, iv., pp. 32 and 985. 



