: of. the b. p. 266 to 268°), 4.5 per cent. alcohols CioHis0, 
a and 12 per cent. sesquiterpene alcohol. 
18 per cent. or 
Oil of Cymbopogon sennaarensis. The grass Cymbopogon sennaarensis, Chiov. 4 
is known by. the name of “mahareb” in the British Soudan. The oil had been described — 2 
by the Imperial Institute in London some years back’), but a closer investigation was — 
only carried out recently by O. D. Roberts”). In odour the herb resembles oil of penny- 4 
royal, but it smells stronger. On distillation of a small parcel of the herb, about ~ 
1 per cent. of oil was obtained at the time; disc 0.9383; p90 + 34°14 sap. v. 14; ~ 
ester v. after acet. 60.2. In 1912 a larger parcel of grass was distilled, the yield being 
1.2 per cent.” disc 0.9422; ap so + 29°38’; acid v. 4.2; ester v. 14.5; after acet. 621. 
The. oil contained presumably n-octylic, decylic and acetic acid in the free state and 
probably esterified octylic, decylic and palmitic acids (m.p. 62.6°); 45 per cent. of the — 
oil reacted with sodium sulphite or sodium bisulphite. The substance recovered from 
tne bisulphite compound by means of sodium hydroxide proved to be identical with 
A*-menthenone which was produced synthetically by Wallach some years ,ago*) and = 
was found by us later in Japanese peppermint oil*) and in camphor oil °*). 
The constants of these three preparations are as follows: — 
Origin of A1-menthenone: b. p. (o ee a&p 
from the oil of Cymbopogon sennaarensis 235 to 237° 0.9387 (15°) + 1944" at 229 — 
from Japanese peppermint oil . . . . 235 to 237° 0.9382 (15°) + 1°30’ ; P 
memiinatioal <: 2.0. ps. isaac eee 235 to 237° ~=—- 0.9375 (199) —_ inactive. os 
The semicarbazones obtained from the Cymbopogon menthenone, the oxime and 
oxamino-oxime, showed the melting points indicated by us. The bisnitroso compound 
of A'-menthenone formed hard white crystals, m. p. 96 to 97°. By oxidation with ~ 
neutral 2 per cent. potassium permanganate solution Roberts obtained the two bodies 
also found by us, viz., y-acetyl-«-isopropylbutyric acid and «-hydroxy-«-methyl-a’-iso-— i 
propyladipic acid, as well as diosphenol (m. p. 82°) and another acid, not further | 
investigated, of the m. p. 126 to 127°. By reduction with sodium and alcohol the 
A‘-menthenone furnished menthol (phenylurethane, m.p.111 to 112°). 
The oil also contained 0.2 per cent. of phenols, from which a benzoyl compan 
of the m. p. 70 to 72° was isolated; lack of material prevented the phenol being more ; 
closely investigated. After slimiination of menthenone and of the phenols an oil 
remained which, after acetylation, had the specific gravity dis0 0.9422; a5. +219 21’. 
Of terpenes, Roberts proved d-limonene (tetrabromide, m.p. 1€3 to 104°) to be present 
in this fraction. Pinene (b. p. 153 to 163°; dis0 0.805; @px20 + 65°15’) also seems to ~~ 
be present, but no nitrosochloride could be obtained. By means of phthalic anhydride — 
an alcohol with a rose-like odour was obtained from the acetylated oil, upon oxidation ~~ 
with chromic acid it furnished a body smelling like tanacetone. The high-boiling parts of © 
the saponified oil contain a sesquiterpene alcohol Ci;H2.O, b. p. 170 to 175° (21 mm.); — 
280 to 285° (ordinary pressure); dis0 0.9544; apxo + 10°48’. Quantitative acetylation 4 
was impossible. Splitting off water by means of phosphoric pentoxide 7 to a SeS- = 
HAW ctianGetadins 
4) Bull“Imp. Inst. 10 (1912), 27; Report October 1912, 52. — %) Journ. Chem. Soc 107 (1915), 1465.2 
3) Liebigs Annalen 862 (1908), 272; Report October 1908, 181. — ‘) Report October 1910,97. — 5) Gildemei 
and Hoffmann, The Volatile Oils, 2"% ed., vol. II, p.-463. ; roy AS 
