- 48 - 
to be taken as settled. But a more recent examination made by 
J, W. Branded) shows that this is by no means the case, and it 
must therefore be assumed that the earlier investigators have had to 
do with the oil of another species of monarda. When distilling lOO lbs. 
of the dried herb, Brand el obtained only 14 cc. oil, equal to a 
yield of 0,03 per cent. It represents a bright red-brown liquid with 
a sweet balsamic odour, whose specific gravity was 0,902 , and angle 
of rotation — 10°. Tests for carvacrol and thymol by Fliickiger's 
method gave negative results. Further experiments could not be made 
on account of the small quantity of oil at disposal. 
Monarda didy?na which is occasionally found in flower gardens in 
Germany, has a very pleasant odour, reminding of linalool and its 
esters, which becomes specially pronounced on rubbing the leaves, 
II. Oil of Monarda fistulosa L. An earlier examination of this oil 
by Bran del and Kremers had led to the detection of two bodies 
which had up to then not been found in essential oils, viz. thymoquinone 
and thymohydroquinone, as well as carvacrol. It was then assumed 
that the dark colour of the oil was caused by a combination of the 
two above-mentioned bodies into a dark-coloured quinhydrone. 
J. J. Beck and J. W. Bran del 2) now have tried to discover 
the distribution of these substances in the individual parts of the plant. 
The red corolla is covered with viscous hairs which under the 
microscope show a reddish-brown colour; these hairs are filled with an 
essential oil which presumably consists of a solution of thymoquinhydrone 
in carvacrol. This is supported by the results of the examination of 
the oil distilled from the petals. 340 grams dried petals yielded 
9,24 grams = 2,71 per cent, of a dark red-brown oil having the specific 
gravity 0,9586, which showed Fliickiger's carvacrol reaction. Larger 
quantities of oil will be produced for a more detailed examination. 
When distilling the leaves without the stalks, a straw-coloured oil 
of the specific gravity 0,9241 (at 20°) and the angle of rotation 
— o°9' was obtained, which contained carvacrol, and which according 
to its colour, cannot contain thymoquinhydrone. 
As the chemical process which takes place in the leaves chiefly 
consists of the conversion of carbonic acid and water into hydrocarbons, 
that is to say, represent a reduction and condensation process, it can 
cause not surprise that the oxidation products of carvacrol found in 
the stalks and petals, are not present in the leaves. Whether later 
on, in the period of growth when the formation of starch in all 
probability takes place much more slowly, thymohydroquinone is also 
produced in the leaves, is a matter which has still to be determined. 
^) Pharm. Review 21 (1903), 109. 
^) Ibid. 1 1 T and 113. 
