2 5 o THE JOURNAL OF PHARMACOLOGY. 



It may be of interest to mention in this connection that regularly every 

 spring there appear in commerce oils which possess abnormal (z. e., too 

 high or too low) specific gravity. Distillers frequently contest the ac- 

 curacy of the determinations of the specific gravity of their oils with great 

 indignation, for they know that the samples with differing specific gravi- 

 ties were taken from the same tank of oil. The simple explanation for 

 this is, that oil of sassafras consists chiefly of a crystallizable body, safrol, 

 which possesses a specific gravity as high as 1.108 ; if this body crystal- 

 lizes from the oil during the cold winter months, it forms, after remelting 

 in warmer weather, a heavy layer of the bottom of the container which 

 becomes mixed with the bulk of the oil only very slowly. Samples drawn 

 from the top of such a container will, therefore, have a very different 

 specific gravity from that drawn from the bottom of the same vessel. For 

 this reason oil of sassafras should always be well mixed before drawing it 

 off if it has been exposed to such low temperatures as to crystallize. 



If large quantities of oil of sassafras are kept cold for a longer period, 

 safrol will crystallize out in very beautiful, strongly refracting, colorless 

 prisms, which sometimes attain a length of more than a foot, and a diam- 

 eter of an inch or more. By repeated treatment in a freezing mixture, 

 with proper fractional distillation of the remaining liquid parts, about 80 

 per cent, of pure safrol can be isolated from the oil. 



Pure safrol is an optically inactive, colorless liquid (melting at 8° C), 

 boiling at 232 C, and possesses a pure, agreeable sassafras odor. Its 

 chemical composition is C 10 H 10 O 2 ; and extended chemical study has 

 proven that it is the methylene ether of an allyl-pyro catechin : 



Derivatives of sassafras oil. — If treated with oxidizing agents, it yields, 

 among other products, by oxidation of its allyl to the aldehydic group 

 CHO, a substance that is highly appreciated in perfumery, the well-known 

 piperonal or heilotropine, and by further oxidation piperonylic acid. 

 When safrol is boiled with alcoholic potash its allyl group, CH 2 = CH, 

 CH 2 is transformed into the isomeric propenyl group, CH 3 CH = CH, thus 

 forming iso-safrol, a substance generally similar to safrol, but of a less 

 agreeable odor, a higher boiling point, 247 ° C, higher specific gravity 

 and higher refraction to light. Upon oxidation it als* yields piperonal and 

 piperonylic acid, but with considerably greater ease, for which reasons it 

 forms the base for the technical manufacture of heliotropine. 



