— 94 — 
of menthol; if a few drops of oil are heated on a watch-glass with 
0,2 gm. pulverised iodine, no violent reaction should occur. 
According to these statements, English as well as American oil is allowed. 
Rosemary Oil (Essenza di rosmarino). Colourless or yellowish- 
green; d^^o = 0,90 to 0,92; soluble in alcohol^) in every proportion. 
^) An initial cloudiness must be attributed to the content of water always 
present in the oil. 
Thymol. Melting point 50° to 51^; boiling point 228° to 230°; 
sparingly soluble in water (about i : 12 00); soluble in less than i part 
alcohol, very readily in ether, glacial acetic acid, and fatty oils. When 
a thymol crystal is ground with a little solid potash and a few drops 
chloroform, a violet colouration should occur; the aqueous solution must 
be neutral, and should not acquire a violet colour when ferric chloride 
is added (test for phenol) ; 0,05 gm. thymol should evaporate completely 
on the water bath. 
Turpentine Oil (Esse?iza di trementina) . Colourless; boils at 
about 160°; d^50 = 0,865 to 0,875; scarcely soluble in water, soluble 
in 8 to 10 parts alcohol, in every proportion in absolute alcohol, ether, 
chloroform, carbon disulphide, essential and fatty oils; on exposure to 
the air the oil resinifies ; neutral reaction ; when kept in a bottle only 
partly full, the oil acquires a yellow colour and an acid reaction; the 
oil must volatilise completely. 
For many purposes the - crude oil may be employed, which is co- 
lourless or faintly yellow, and which on evaporation leaves about 
2^/q residue. 
An old ozonised oil which colours potassium iodide starchpaste 
blue should also be kept in stock. 
Novelties. 
In the last six months a whole series of new or rare essential oils 
has again been submitted to examination in our laboratory, and the 
most interesting of these are mentioned below. 
From Japan we received once more a 
Yomugi Oil. It agrees well with the sample referred to in our 
last Report (p. 78): d^go = 0,9126; ap = — 18° 50'; acid number 
= 1,32; ester number — 16,19. The solution in 90 ^/q alcohol, which 
is at first clear, becomes cloudy when more solvent is added. 
With regard to the species of plant from which the oil is obtained, 
opinions differ. Whilst according to J. J. Rein^) yomogi is the Japanese 
^) J.J. Rein, Japan, from travels and studies. Leipzig 1886, II, 160. 
