: one eg Ai Me 1 ES ly a a 
_NoTES ON, SCIENTIFIC RESEARCH. in 91 
os Eo Ncw, the eagit of the C.H,O added is mioteetiaely proportional to the free alcohol 
: presen in the peer oil, 
m:42 = alcohol in 1 g. oil: x 
so that the weight of the free alcohol in i g. oil | 
_mxXx m X< (E.V.II— E. V. I) 
os 
- on aa Gd SC (PV) 
Po 
2: 
- 
£ 
hence the percentage of free alcohol 
m X<(E.V.I—E.V.1) 
~ 0.42 < (1333 — E.V. II) 
As dealt with above, with low ester content in the oils the differences in the 
values are only slight, so that from a purely practical point of view we suggest to 
continue stating the’ oil content of total alcohols without taking into consideration the 
= esters present in the original oil, i. c., to state the values found straight from the EW: 
of the acetylated oil. Only with oils eh in esters, such as geranium oil, considerable 
Zs _ discrepancies become manifest, and in such cases, we admit, it is recommendable to 
> _ state, in addition to the apparent content of alcohols as calculated from the ester 
: value after acetylation, the correct alcohol content, such as calculated by Tusting 
= ~ Cocking’s method. 
: The only method for the determination of the volatile oil content of citrus fruits 
ai is, as C. P. Wilson and C. O. Young") have found, distillation of the ground fruits with 
3 steam. Several attempts were made to extract the ground peel by means of some 
_ Organic solvent, such as alcohol, ether, benzene, gasoline, chloroform, or carbon tetra- 
chloride. It was found, however, that invariably a large amount of water was dissolved 
z by the solvent, even when benzene, carbon tetrachloride, or similar solvents were used. 
five practical method was found to drive off this water without loss of oil. The authors 
then tried to mix the ground peel with anhydrous copper sulphate or sodium sulphate 
and to extract the mixture as before; but ton large amounts of dehydrating material 
were required, which caused packing or caking and prevented complete extraction. 
The most satisfactory method was as follows:— The whole fruit is passed three 
_ times through a fine cutting food grinder mixed thoroughly; immediately after grinding, 
200 g. of the sample is weighed into a 1/2 liter flask and mixed with 700 cc. of water. 
_ The oil is then rapidly distilled off by steam, tho flask being gently heated; the distillate 
is collected in a special oil flask resembling a Babcock milk test. bottle, the body of 
82 which had a capacity of 200 cc., the neck 2 ccm., the latter being graduated in */10 cc. 
_ As soon as the distillation of the oil is complete, the oil is brought into the graduated 
y “neck of the bottle by addition of water and whirled in a centrifuge until all of the oil 
has collected in a clear layer. The volume of the oil is read off and the weight cal- 
"culated by the formula Weight = Volume << 0.849 >< 0.996, where 0.849 is the mean 
- specific gravity for California lemon oils, and 0.996 the factor correcting for determina- 
_ tions made at 25°/25° C. in air. In exact work, the specific gravity of the oil should 
Rise predetermined for the particular kind of fruit used. 
‘; __ When the ground peel alone is distilled, and the percentage calculated back to 
‘the entire fruit, the results obtained are usually too low owing to the loss of oil 
_ during the peeling. 
: Ten samples of the Californian Eureka lemon gave distilled oils with specific 
re ‘gravities, at sila C., from 0.8462 to 0.8504, average 0.8487; 12 samples of the Lisbon 
ne 
taint ate eed es 
1) Journ. ind. eng. ‘Cictuisthy 9 (1917), 959. 
