A92 QUEENSLAND AGRICULTURAL JOURNAL. [1 Noy., 1901. 
Science. 
PERFUME PLANTS. 
Mons. J. Chapelle, Departmental Professor of Agriculture of the Var, 
France, presented a very interesting and valuable report on the perfume industry 
in France to the sixth International Agricultural Congress held at Paris in 
July, 1900. This has been republished in the Révue Générale Agronomique, 
from which journal we take the following extracts, which will doubtless prove 
of value to those who are interested in scent-farming :— 
EXTRACTION OF PERFUMES AND Essenrran Ors. 
The extraction of the scents contained either in the branches, in the leaves, 
and, above all, in the flowers of plants [enumerated in a previous article—Rd. 
Q.A.J.] is a delicate and complex operation. 
According to the very just definition of M. Rouché, chemical engineer, 
scent should possess the two following qualities :— 
1. It should recall the true odour of the substance from which it is 
extracted. 
_ 2. It should, when exposed to the air, be completely unchangeable, and 
of sufficient permanence. 
In two words, it must be perfect and durable. 
These two essential qualities are realised in a more or less perfect manner 
by the aid of the principal methods of extraction in general use—yiz., distilla- 
tion, maceration or hot process of extraction, absorption or cold process, disso- 
lution, expression. 
The flowers gathered under favourable conditions of blooming and 
sunshine must be treated at once, to avoid withering, the alteration of the very 
subtle perfume principle contained in their epidermic cells. 
Distillation is resorted to in the case of flowers or plants which undergo 
no alteratioa in the presence of steam or from a high temperature. 
By this process are treated certain scented woods, leaves, and plants, such 
as mint, lavender, rosemary, thyme, &c., rose and orange flowers. 
The many details of this operation vary, so to speak, with each plant, and 
the apparatus used is consequently of different construction. 
For the distillation of wild plants, lavender, rosemary, thyme, &c., very 
primitive stills with open fires are used in the country. But in the great 
factories which treat daily a considerable quantity of very delicate perfume 
plants, large and most perfect apparatusare employed which enable the operator 
to avoid burning, the contact of the contents with the sides, the agglomeration 
of the substances treated, &c. 
To distil, in certain cases, in the air or in a vacuum, in order to obtain the 
finest scents. ‘lo carry out methodical distillations and to separate the different 
products, to rapidly collect the essential oils, &e. 
The vessels, or Florence flasks used for collecting the latter, are of different 
shapes, but all are on the same principle, which is to effect the separation of 
two fluids of unequal density during the distillation. 
Maceration or Extraction by Heat.—Certain flowers such as cassia, violets, 
jonquille, cannot be distilled owing to the small quantity of perfume contained 
im them, and to the perfume being likely to undergo a change in a high 
temperature. In this case advantage is taken of the property possessed by fatty 
bodies of absorbing the essential oils by simple contact with the odoriferous 
plants. 
For preference, lard is used which has to undergo a special preparation to 
remove its odour and to prevent its becoming rancid. 
