— 91 — 



the other products of distillation (Robert erroneously includes cerotinic 

 acid among these fatty acids). He recommends the replacement of the 

 present method by a process of extraction in which the powdered root 

 is repeatedly exhausted with a suitable solvent. In lieu of light petroleum 

 (the material most frequently used for extracting, which however, is 

 highly inflammable), Robert recommends di- or tri-chloroethylene, which 

 are non-inflammable, although they have the drawback of liberating 

 some hydrochloric acid in the presence of moisture. According to him, 

 these two solvents are now used in all German works. As soon as the 

 solvent has absorbed a sufficient porportion of soluble constituents from 

 the orris root it is either distilled in vacuo or simply evaporated, the re- 

 sidue being then treated with alcohol to remove any wax-like or resinous 

 constituents. The alcoholic extract is either used as such, or the alcohol 

 is distilled off, leaving an extract of orris of a very agreeable odour, from 

 which the pure essential oil may be obtained by rectification. Robert 

 regards it as a special advantage of this method that it enables the per- 

 fumer to prepare concentrated extract of orris root for himself without 

 much trouble. As the residual extracted powder is not worthless, but 

 may be used for the manufacture of cheap preparations, the method is 

 further said to be also of financial advantage. Owing to the powder being 

 of a pale colour, it is specially suitable for mixtures, which should possess 

 as little colour as possible. 



We reproduce Robert's views without comment, but in connection 

 with his statements we may publish the analysis of an orris root powder 

 which was recently submitted for our examination and opinion because 

 it was suspected on account of its exceptionally low price, and had obviously 

 been partly extracted. Microscopically, the sample (I) presented no material 

 differences from two samples (II and III), prepared by ourselves for purposes 

 of comparison, although in the case of the former the presence of numerous 

 small lumps of starch attracted attention, such lumps occurring only very 

 sporadically in the authentic powders. But the percentage determination 

 of the ashes and the ethereal extract 1 ) yielded quite other results, as 

 shown on the subjoined table: — 



Acid No. Ester No. 

 of the ethereal extract 

 I ... 2,1 % l,5°/ 56,0 112,0 



II . . . 3,1 % 3,7% 53,0 113,0 



III ... 3,45% 3,4% 54,2 123,5 



It will be seen that in the sample under examination both the residue 

 of incineration and the ethereal extract were considerably less than in 

 the two samples prepared by ourselves, the quantity of ethereal extract 



Ash Ethereal extract 



J ) Ascertained by extraction in Soxhlet's apparatus. 



