( 7 ) 
The distillation is carried out in a still, connected 
to a condenser around which cold water circulates. 
The still is provided with a false bottom, on which 
the plant material is placed. Steam is passed 
through the still, thereby volatilising the oil. The 
mixture of oil and steam is condensed, when the 
oil — not being miscible with the water — rises to the 
surface or sinks to the bottom according to its 
density. 
Mechanical processes are employed in the case of 
such oils as lime and lemon, in which the essential 
oil is present in the rind of the fruit. There are 
two or three variations of this process, the most 
common being the so-called “ ecueille ” process. An 
ecueille is a saucer-shaped vessel, usually made of 
tinned copper, fitted with a hollow stem, the inside 
of the saucer being covered with short spikes. The 
fruit is placed in the ecueille and, with a rapid 
circular motion, the oil cells are ruptured, the oil 
exuding and running dowrn into the hollow stem. 
Extraction processes involving solvents are em- 
ployed principally for extracting the scent from 
flowers of delicate perfume, which would be impaired 
were the flowers to be subjected to steam distillation. 
Two kinds of solvents may be employed; volatile, 
such as alcohol, benzene, ether or chloroform; and 
non-volatile, such as neutral animal fat. 
In the case of volatile solvents, the extraction 
consists, as in the case of fixed oils, in allowing 
the solvent to percolate through the flowers. The 
solvent is distilled off and the residue utilised for 
the manufacture of so-called floral essences. 
