The herald., 1896-08-15

and may be as good as or better than
eucalyptol
THE different and In some cases con-
Trajectory reports / have seen on the
eucalyptus oils induced me to secure
the aid of 8. M. Woodbridge, Phi. D., in
making some examinations of the oils
taken from species identified here L give
the result of the doctors work in his
own words:
Chemical authorities in technical
works and encyclopedias have always
divided the oils from the products of
growth in two classes:
l. Fixed or fatty oils and
2 Essential or volatile oils
The fixed or fatty oils are described as
follows: Characterized by their ability
to communicate to paper and like sub
stances permanent translucent grease
spot, and they cannot be volatilized ex-
cept by destructive distilation" at high
temperatures.
The essential or volatile oils are de-
scribed as not being oleaginous to the
touch and make no permanent grease
spot; they are distilled at various tenn
peratures, unchanged.
Accepting these definitions as true,
and 1t does not appear that they have
ever been questioned, it is difficult to see
how the oils of the various eucalypti can
be defined under either Of the above
classes. or large variety that have
been tried all are unctious to the touch
but leave no permanent grease spot on
paper nor does it require destructive
| distillation" to volatilize the greater por-
| ton of them, although the last portions
of all of them that have been tried, re-
| quire destructive distillation;" nei-
| ther, on the contrary, do they volatlize
at ordinary temperature nor volatilize
at all unchanged, but a variety of pro-
ducts come over at different tempera-
70 n hnxr t11k kzsI -,
ter each of which has very different
characteristics from the oil and from
every other product obtained.
! The eucalyptus oil might be described
as compound OIL some Of the con-
| stituents of which volatilize at various
| temperatures with residue that cannot
be volatilized except by destructive dis
tillation."
| The eucalyptus oils of commerce are
! obtained from the leaves of the different
varieties of eucalyptus. by distillation
| in an ordinary still and condensng coil
The best results were obtained when the
steam pressure in the boiler was main
| tained at not less than eighty pounds
| and when the leaves were put in the still
loosely in such way that they
could not pack down. Repeated trials
show that by crowding the still a loss
| of between 25 and rs per cent resulted;
| /. e., less oil would come over when the
ledNeS were packed III the Stlll, OF
! allowed by their own weight to
pack down. This packing of the
lea%es can be avoided by putting in !,
| layer of leaves, say, one foot in thickness,
| then porous frame or lattice rack made
to rest on the sides of the still or cage.
On this frame ar rack another layer of
leaves could be placed, and on these an
other frame, and so on, until the cage
or still was filled. The reason for this
want of recovering all the oil in closely
packed still will be readily understood
when it is considered that the oils are
volatile at the temperature of the
steam within the still. but are taken up
mechanically by the steam and carried
over with it. The pressure in the still
never exceeded fifteen pounds therefore
the heat could not have exceeded 24S
degrees F., temperature at which only
very small portion of oil will vola tilize.
The following table will show the
amounts of oil yielded by some twenty
six varieties of eucalyptus, together
with their specific gravities and colors: