— 86 — 
political economy, that the production of most perfumes by syn- 
thetical or artifical means has rendered it possible to effect a very 
considerable reduction in the prices of the aromatics which up to that 
time had been looked upon as a privilege of the wealthy classes; 
and further that, in spite of the fact that the artificial article in many 
cases (as with vanillin or coumarin) is richer than the natural product, 
yet both move onwards, each following its own path. The cultivation 
of vanilla has not been curtailed by the discovery (^f vanillin, although 
in the case of dye stuffs restriction has followed the competition-struggle 
between the natural and the artificial product; and of coumarin, fresh 
sources are again and again discovered in nature, which are success- 
fully turned to account. But scientific research became supremely 
important when it was a question of detecting foreign admixtures in, 
or adulterations of, the products of the perfume industry. 
The lecturer further discusses in detail the synthetic production of 
the most important perfumes, which we can here only mention briefly. 
He describes for example the production of artificial musk by Baur, 
by nitrating certain homologues of benzene; that of ionone, obtained 
in 1893 by Tiemann by converting the condensation product of 
citral with acetone by means of dilute sulphuric acid; further, the 
production of vanillin, also by Tiemann, first from the cambial sap 
of conifers, subsequently from eugenol, and later still from isoeugenol; 
that of heliotropin or piperonal, by oxidation from safrol or isosafrol; 
and finally that of coumarin, by condensation of salicylic aldehyde 
with sodium acetate and acetic anhydride, and of many other aromatics 
which are important for purposes of perfumery. 
It will be seen that Dupont's lecture deals almost exclusively 
with known facts; at the same time we believe that, in reproducing 
the main points of his paper, we may have communicated matter 
which will not be entirely devoid of interest to at least some of 
our readers. 
C. Mann^) has communicated a method for the quantitative 
estimation of essential oils in spices, or in am^ other drug whose 
content of essential oil has to be determined. His method is as 
follows: the body to be examined is pulverised as required, mixed 
with small pieces of pumice stone, and exhausted in the usual manner 
by steam distillation. To the aqueous distillate, conveniently cooled 
to about -]- 10°, 25 per cent of its weight of pure common salt are 
added, and then the solution is extracted for half an hour with a 
measured quantity rhigolene, i. e. very volatile petroleum ether of the 
boiling point of about 20 to 35°. The extraction -liquid, increased 
^) Archiv d. Pharm. 240 (1902), 149. 
