THE ODOUR OF ROSE. 61 
placed; 2, a closed vessel containing purified methyl chloride; 3, 
a closed vessel for the reception of the solvent after it is charged 
with the odorous principle of the flowers ; 4, a pump for creating a 
vacuum in vessel no. 3, by which means the chloride is vaporized 
and the vapour compressed in a refrigerating condensing-worm, 
from whence it is conducted back ina liquefied state into the vessel 
no. 2 which originally contained it. This latter portion of the 
apparatus (and it is a very important portion) is the refrigerator 
which was illustrated in ‘La Nature,’ June 21, 1879. The action 
of the apparatus is as follows:—The digestor, being filled with 
flowers, is closed; then, by means ofa valve, the liquid chloride is 
allowed to flow from vessel no. 2 into the digestor and to cover the 
flowers. After two minutes’ digestion the liquid, then charged with 
the perfume, is allowed to flow into vessel no. 3. A fresh charge of 
methyl chloride is then introduced over the same flowers, and is 
afterwards passed into vessel no. 3; this is repeated until the 
flowers are exhausted of their aroma. Finally, a vacuum is created 
in the digestor to remove the remnant of the chloride mechanically 
contained by the flowers, and the vapour is forced into the refri- 
gerator ; a jet of steam is then passed through the spent flowers, 
all resulting methyl-chloride vapour sucked out by a pump, and, 
after desiccation, liquefied by pressure. The liquid containing 
the perfume in solution in the third vessel is evaporated by ex- 
haustion ; to effect this, the vessel is surrounded with water kept 
at a temperature of about 30° C. while the pump is working; the 
evaporation of the chloride is then rapid. When the pressure- 
gauge attached to the vessel registers a vacuum of half an atmo- 
sphere (it having originally marked a pressure of 3 or4.atmospheres), 
the operation is finished. On opening the vaporizer, the perfume 
is found mixed with fatty and waxy matters. This mixture treated 
with cold alcohol yields up the perfume in all the fragrance and 
sweetness which it originally possessed in the plant. 
At the meeting of the Société d’Encouragement, December 26, 
1879, Messrs. Schneider and Naudin, chemists, of Montreuil-sous- 
bois, make a claim of priority as regards Massignon and Vincent’s 
process. Schneider and Naudin’s patents are dated April 12, 
1879*, May 21 and 26+, May 30 f, and additions to these patents 
were made on June 14, September 19, and October 14, 1879. 
* No. 130187. + No. 180873. t No. 180967. 
