No ScIENTIFIC NOTES oN ESSENTIAL OILS. 33 
F that it can rit once be iene ied up. The superfluous fruit, which is not put to 
any use in the écuelle process, is used for the preparation of marmalade or orange syrup. 
The machine consists of the four following important parts: — 
Beek (f) A rapidly revolving, 11 ft. long drum, which scrapes the peel off the fruit. 
(2) A connecting soict spindle of the same length, which moves the fruit i i 
the drum, and takes away the peelings. 
- (3) A specially constructed table, which serves as a eacdartli for the fruit whilst 
passing through the machine. | 
(4) A contrivance for adjusting the space between ie spindle and table to the 
size and shape of the fruit. 
_ Experience in the use of’ the machine has shown that the peel removed by the 
first third of the length of the drum contains about 76 per cent. of the oil, that removed 
- by the second third about 23 per cent. and the peel removed by the remaining third 
contains less than 1 percent. of the oil. Hence only the peel removed by the first 
2/3 of the drum is used in the further manufacture; it is stirred up with a little water 
- and is distilled in a special vacuum apparatus. The best results are obtained when 
_ the body of the still is heated externally simultaneously with the use of direct steam. 
The distilled oil is mixed with 20 per cent. of its weight of fresh unextracted peel, 
_ macerated and filtered. The oil has a lemon-yellow colour after this treatment, with 
a light brown shine, a very fine odour, and the characteristic aromatic taste of oranges. 
As during maceration about 10 per cent. of the distilled oil is retained by the fresh 
peel, the filter residue is compressed into cakes, and subjected to steam distillation. 
In this way almost the whole of the oil in the peel can be obtained. In order to 
separate the expressed oil, obtained as a thick emulsion, from the water, it is heated 
- to 90° in the water-bath and ‘/10 of its volume of a 10 percent. gelatine solution is 
added, and a fourth of its volume of a 10 percent. tannin solution. In this way the 
substances which bring about the emulsification are Pas iarees and the essential oil 
can be obtained without loss by pressure. The rhizome of “saw palmetto” proved 
itself to be a cheap source of tannin, since it contains about 7.6 per cent. of tannin. 
A comparison of the oil obtained by vacuum distillation, and that obtained by 
_ pressure with a hand-pressed oil from Italy showed that all samples had the same 
fine characteristic aromatic taste and smell. The machine-pressed oil excelled both 
_ other samples in its fine fruity aroma. | : 
ees 
Colour Smell Residue on 
: ; 3 di50 [@]p2507) evaporation 
d ake of es Lemon yellow’) Characteristic © 
% smell of oranges 0.8415 115°6' 1.73 per cent. 
q = ere oil . Lemon yellow ditto 0.8423" ASO AB ANON fe 
with a slight ; 
brown glint 
5 ae oil . Reddish yellow Characteristic 
smell of oranges; bai 
fruit flavour 0.8445 109936’ 2.90 ,,_,, 
__ Hood comes to the conclusion that a good marketable article is obtained by the 
‘vacuum process, and a thoroughly excellent oil by pressure. If the good yield and 
1) Remarkably light for Italian oil; Italian oils mostly have a brownish tinge. — 2) From this as original 
rotation would be reckoned: @4p+ 96°51’, ap +97°7’ and ap + 92°33’. 
Be 3 
* 
“es r hi 
{7 ae 
