68 ODOROGRAPHIA. 
oil. An inferior oil is sometimes obtained by roughly rasping the 
surface of fruit which has undergone the écuelle operation, and 
sometimes by rasping fresh fruit, and distilling the result with 
water, which yields an oil very inferior in perfume and in value ; 
it is called “ Essence distillée,” to distinguish it from the above, 
which is called “ Essence au Zeste.” Although the distilled oil 
is still considered inferior, experiments made in London by Moss* 
by distilling peel from fresh lemons, the cellular tissue of which 
was torn to free the oil, resulted in a product which was con- 
sidered equal to or finer than the Italian oil made by the cold 
process. (Its specific gravity was estimated by Dr. Tilden at °852 
at 20°C.) This experiment led him to believe that the inferior 
fragrance of foreign distilled oils was partially attributable to 
the construction of the stills. Products distilled on a large 
scale are undoubtedly affected in quality by the form of the 
still and the method of manipulating it ; but probably in the ex- 
periment made by Moss every lemon was carefully peeled by hand, 
and no trace of acid juice of unripe fruit allowed to enter the still. 
A sort of écuelle on a larger scale, capable of operating on six or 
eight fruit at a time, or about 7000 per day, is used for extracting 
Bergamotte oil. It consists of a metal vase perforated with small 
holes at the bottom, and is provided with a heavy rotatory lid- 
communicating by cog-wheels witha handle. There is a channelled 
groove round the inner circumference, for the reception of the 
fruit; the inner surface of the lid and the groove are fitted with 
short metallic blades projecting about 15 millimetres. The rapid 
rotation of the lid, which presses on the fruit, causes them to 
revolve and become lacerated at all points, and the liberated oil 
flows through the perforated bottom into a receiver. Oil thus 
obtained is greener than formerly obtained by the éponge process. 
An apparatus called the Strizzatore termo-pneumatico (thermo- 
pneumatic extractor) was invented by Dominico Monfalcone for 
the extraction of oils from all varieties of Citrus fruits—the 
advantages stated by the inventor being that from a given weight 
of fruit double the quantity of oil is obtainable than by the older 
method of the éponge, also the economy of an immense deal of 
time and labour. The product is said to be equal in quality to 
that obtained by mechanical means alone. The apparatus is 
described as follows :—A is a hollow cylinder of sheet iron, the 
* Pharm. Journ, 20th March, 1879, 
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