— 23 — 
is consequently the first time that 1-citronellal has been detected as 
a constituent of an essential oil. The melting point of the semicarb- 
azone which was produced for the further identification, and was 
prepared according to Tiemann's directions, was found at 74°. 
In the portions of the oil which did not react with bisulphite 
solution, cineol could be detected with certainty; they probably also 
contain limonene, or a mixture of limonene and dipentene. 
A sample of citronella oil which takes about an intermediate place 
between Ceylon and Java citronella oils, was received by us some 
time ago from the Government Laboratory in Jamaica. We found for 
this oil: d^go = 0,8947, ajy — 4° 16', and Uj^^o^ 1,47098. It also 
showed a low acid number, and contained 86,4 per cent, total QoH-j^gO, 
with a citron ellal-con tent of 25,43 per cent. 
In a note appearing in the ''Tropenpflanzer" ^) we find that in 
the Botanical Garden at Victoria in the Cameroons, under the name 
Andropogon citratiis, a species of grass is cultivated, which, according 
to an examination by S trunk, yields an oil which is seemingly identic 
with citronella oil. S trunk distilled 10 kilos of the fresh grass with 
water, and obtained a yield of 0,38 per cent oil. With the primitive 
means at his disposal he was able to ascertain that this oil contains about 
15 per cent, of an aldehyde, which appears to be identic with citronellal. 
According to the foregoing the grass cultivated at Victoria, of 
which it had not hitherto been possible to determine the species as 
the plant never reached the flowering stage, may possibly be identic 
with Andropogon Nardus L., w^hich in the East-Indies is cultivated on 
a large scale for the production of citronella oil. 
It has repeatedly attracted our attention, that when it is a question 
of their origin, the Andropogon grasses are frequently confounded with 
each other. The thought which first occurs is, that such confusion 
is caused by the omission of the name of the author after the desig- 
nation of the species. But this does not apply in every case, for 
there are some exactly-defined species indicated as the mother-plants 
of oils which, according to our information, could not possibly be 
produced from them. We will give some examples of this. Tschirch, 
in his work 'Tndische Heil- und Nutzpflanzen" mentions on page 128 
Andropogon Schoenanihits L. as the mother -plant of lemongrass oil. 
The same statement is made in the chapter Gramineae edited by 
Hackel, in Engler and Prantl's "Natiirlichen Pflanzenfamilien" ; 
the oil obtained from it is said to be met with in commerce as 
^) Volume 7 (1903), 37. 
^) Berlin 1892. R. Gaertner. 
