108 ODOROGRAPHIA,. 
ointment, which is termed “ butter of Iris,” and possessing the 
characteristic odour of orris. This product only amounts to a 
little more than ] per mille of the root used, and consists princi- 
pally of myristic acid, which is perfectly odourless, and a minute 
quantity of a brown essential oil to which the entire fragrance of 
the root is due—the proportion of this oil in the root is estimated 
at being possibly not more than 1 in 10,000. 
The myristic acid can be separated from the crude product 
(butter of Iris) by repeated crystallizations from alcohol and 
purification by animal charcoal. The obstinately adherent volatile 
oil is concentrated in the mother liquids, and the crystals become 
less and less odorous until finally they have lost all aroma. The 
pure crystals melt at 52° C., and their composition is represented 
by the formula C,,H.,0,—which is that of myristic acid. The 
effect of the presence of the smallest quantity of the adhering 
volatile oil, or a trace of Jauric acid melting at about 44°C., 
which may easily accompany the myristic acid, must be to lower 
the melting-point. The original details of the investigation contain 
the following annotation :— The question arises how the myristic 
acid, which can only with difficulty be distilled without decom- 
position, passes over with the oil. The explanation of this is to 
be sought in the phenomenon of diffusion. (Rose-oil is similarly 
accompanied by a stereoptene which is difficult to volatilize by 
itself.) An alcoholic solution of the pure crystals possessed no 
rotary power, and energetically reddened litmus paper moistened 
with alcohol. 
“The occurrence of myristic acid in the distillate is probably due 
to a fat which is present in the root, and is split up by the vapour 
of water. The quantity of this fat must be very small, since 
300 grams of orris-root powder exhausted with carben bisulphide 
gave a soft perfumed resin, but neither free myristic acid nor 
neutral fat could be detected. The carbon bisulphide extract was 
digested with sodium carbonate and alcohol, in order to obtain a 
solution of sodium resinate and myristate, from which the acid 
sought could be precipitated by acetic acid. If myristic acid were 
present, it would, on prolonged digestion of the turbid acid liquid, 
gradually rise to the top as an oily layer. This, however, did not 
take place even after several days; the brown resinate slowly sank 
to the bottom as a pulverulent mass, and the liquid became clear 
without yielding an oily layer.” 
Carbon bisulphide appears to be unsuitable for the removal of 
