40 ODOROGRAPHIA. 
by the addition of hot and cold water, and read off on a Réaumur 
thermometer. In a pure oil the congelation commences in three 
minutes, and at the end of ten minutes should be so complete 
that on turning the flask upside down the contents should not 
run out. Payment is made according to the degree marked by 
the thermometer when this congelation is arrived at; the degree 
of congelation indicating the degree of adulteration. 
Mr. Christo Christoff, of Kézanlk, states that ‘‘ formerly paraffin 
was added to the otto, in which it dissolves very well, and in spite 
of the presence of geranium the congelation takes place at 65° to 
68° F., but the crystals are opaque, of a dirty yellow, and break 
up, forming a sort of muddy substance which collects at the top 
of the flask. The simplest method of adulteration consists in 
adding to the roses to be distilled some white roses, the product 
from which, though less fragrant, is much richer in stereoptene 
than that of the red rose ; furthermore, this otto, which normally 
would congeal at 68° F., can, by geranium, be brought down to 
65° F., and remain still within the prescribed limits.” The otto of 
rose manufactured in Germany may appear finer than the Turkish 
from the fact that it is pure, distilled with greater care; doubtless 
the green parts of the flower (calyx, receptacle, and stalk) are 
separated, and a still capable of distilling the oil at reduced pressure 
is used, and many precautions taken; but to develop the true 
fragrance of the rose in perfection requires the full power of the 
sun and greater heat than the climate of Germany can ever 
furnish. No doubt localities might be found in Persia or in 
Tunis where the climate and soil are suitable to the growth of the 
rose, and with good stills and trustworthy European managers a 
pure otto could be produced at a very remunerative price, and the 
Oriental fraud and jugglery with “ geranium oil” put an end to 
—as far as the London market is concerned. Further, the stereo- 
ptene might be separated, as it is a perfectly odourless product, 
and otto so sold “ sine stereoptene” would be more difficult to 
adulterate and yield no deposit in bouquet preparations. 
Rose Cuirure 1n FRANCE. 
As before observed, the cultivation of the rose in the south of 
France, especially in the neighbourhood of Grasse, has enormously 
increased. Otto of rose and rose-water are made, but the flowers 
