soluble in water, soluble in about lo parts alcohol^), in every pro- 
portion in absolute alcohol. 
^) It is clear from the specific gravity required for the oil that the lemon oil 
expressed from the peel of Citrus limonum Risso (Essenza di limone) is meant, 
as the various citron oils, — which for the rest are not a commercial article at 
all, — are partly heavier, partly lighter than the oil mentioned above. Compare 
our Reports of October 1895, i8; April 1902, 30; April 1903, 34. 
^) Lemon oil has a bright yellow colour; distillation of the oil is quite irrational, 
as such oils deteriorate very rapidly and acquire a disagreeable pungent odour. 
^) The solution in go ^j^ alcohol is not always perfectly clear, owing to the 
presence of slimy and vegetable wax-like constituents. 
Clove Oil (Essenza di garofani). Yellowish, gradually changing 
to brown on exposure to the air; dj^go = 1,060 to 1,070^); soluble 
in alcohol in every proportion; 4 drops oil should make a solid 
crystalline mass with 4 drops concentrated alcoholic potash solution. 
Identity-reaction and test for phenol in the usual manner. 
^) The specific gravity shows that only oils with a particularly high eugenol- 
content are allowed. 
Eucalyptol. Colourless; d^50 = 0,930^); boiling point 176° to 
177^2^; almost insoluble in water, soluble in absolute alcohol, ether, 
chloroform and fatty oils; when cooled in a mixture of ice and common 
salt, eucalyptol should solidify into a crystalline mass^) consisting of 
long needles melting at — 1°. If in a test tube moistened on the 
inside with eucalyptol, a little bromine vapour is introduced, brick-red 
needle-shaped crystals should be formed. With an equal volume carbon 
disulphide eucalyptol should form a clear solution (test for water). 
^) The specific gravity of pure eucalyptol free from water, lies between 0,928 
and 0,930. 
^) The Italian Pharmacopoeia unfortunately does not indicate the height of the 
barometer to which the boiling points relate; for this reason we would point out 
specially that all statements relating to the boiling point, if nothing is said to the 
contrary, refer to the normal height of the barometer (760 mm). Further, it 
should be noted that with such determinations the whole of the mercury thread 
which comes under consideration must be enveloped by the vapour of the liquid, 
which is accomplished by using normal thermometers with shortened scale. Other- 
wise the corrections necessary have to be made so as not to arrive at incorrect results. 
3) The solidification must sometimes be started by the introduction of a crystal 
of solid eucalyptol. 
Oil of Juniper berries (Essenza di ginepro). Colourless or 
faintly greenish-yellow, becomes viscid under the influence of air and 
light, and then acquires a more yellow colour; d^^go = 0,865 to 0,885 ^); 
soluble in nine parts alcohol 2), in one part carbon disulphide^). 
^) The oils of juniper berries are also frequently lighter; we have had in our 
hands good distillates down to 0,860. 
^) Generally, quite freshly distilled oils only answer these requirements. 
^) A possible cloudiness is due to the slight content of water which is almost 
always present in the oil. 
