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F SCIENTIFIC AND OTHER NOTES ON ESSENTIAL OILS. 17 
of their own manufacture from 72.2 to 86.4 p.c. distilled within the above-mentioned 
limits of temperature. The oils themselves had been obtained to the extent of 9.5 
to 15p.c. and showed the following constants: dis0 0.9233 to 0.9268; %) — 27.4 to 
— 37.62. Two of these oils contained no parts boiling below 250° at all, the remaining 
two showed 12.8 and 18.0 p.c. of such fractions respectively. 
” Essential Oils, Sicilian and Calabrian. 
Lemon Oil. A novel and mysterious method for the manufacture of lemon oil 
has been worked out by Liotta’). The lemons are pounded in a large vessel and 
mixed with an acid, the composition of which is kept secret. This acid is said to 
produce the separation of the oil, which rises to the surface and is removed. A substance 
is then added which liberates the acid, so that it can be used again! The residue, 
consisting of lemon juice, pulp, peels, 8c. is sold to manufacturers of citrate of lime. 
It is said that with this new method the yield of oil is 2'/2 p.c. higher than with 
the old method of pressing by hand. As regards cost, this is said to be but 2.3 cents 
per 1000 lemons, the operation lasting only 22 minutes. By perfecting the method 
and by working on a large scale it is expected that the operation can be carried out 
within about 12 minutes. 
As long as no further particulars are known about the mysterious acid and the 
substance used for recovering it, we may say this new method smacks somewhat of 
a fairy-tale. 
Eucalyptus Oil. The resorcinol method published by us a number of years ago’) 
has on repeated occasions been the subject of criticism on the part of English 
chemists*). These gentlemen will not admit the method even in its modified form 
(determination of eucalyptol in the fraction boiling between 170 and 190°) on the 
pretext that it yields insufficient results. They base their verdict merely on the fact 
- that they arrive at different results when separating the eucalyptol with phosphoric 
acid, but they fail to adduce proofs for the reliability of the phosphoric acid method. 
We have tested this latter method very thoroughly and have ascertained beyond doubt 
that correct results are obtained with it by accident only. Every unbiased observer 
who has handled the addition product of cineol separated from eucalyptus oil by 
means of phosphoric acid will agree with our statement. It would be like carrying 
coals to Newcastle, were we to revert to the subject once again at great length, suffice 
it to refer once more to what we said in our Report of October 1907, page 46. On 
the other hand we have produced, in above-mentioned Report as well as in our Report 
of April 1908, voluminous proofs of the resorcinol method being useful in its original 
form, if, besides cineol, chiefly hydrocarbons are present, such as is the case with oils 
of the amygdalina variety, whereas, if at the same time oxygenous bodies are present 
(alcohols, aldehydes) correct results are obtained if the fractions boiling between 170 
and 190° are subjected to the modified resorcinol test. Quite acceptable values are 
1) Commerce Reports No. 65 of the 19? of March 1915 (Washington). — 2) Report October 1907, 47; 
April 1908, 50; Gildemeister and Hoffmann, The Volatile Oils, 2.4 ed., vol. I, p. 601. — %) Comp. Report 
April 1908, 52; October 1910, 67; April 1913, 62. 
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