290 ODOROGRAPHIA. 
almost entirely between 189° and 192°, a small quantity of a much 
less volatile and resinous body remaining in the still. These 
authorities describe the oil as “an oxygenated body having the 
formula 2(C,,H,;)5H,0, this formula answering to that of a hydrate 
of terebenthene or of an isomer. The oil slowly absorbs oxygen 
and becomes resinified. It does not combine with sodium bisul- 
phite. The red-brown coloration which it takes under concen- 
trated sulphuric acid is analogous to that which turpentine pro- 
duces with the same acid.” The odour of the oil is likened by 
Poisson to a mixture of lemon and jasmin, but by others it is 
thought to resemble bergamot. 
The odoriferous constituent of oil of Mexican Lign-aloe was 
discovered by Semmler* and termed Linalool. This has recently 
been isolated by Messrs. Schimmel, who find that it is the prin- 
cipal constituent of the oil, and is the sole bearer of the most 
delicate odour of the latter which is so valued in perfumery. It 
is described as an almost colourless liquid, very soluble in alcohol, 
of sp. gr. 0°878 at 15° C.; boiling-poimt between 197° and 
198° C.; optical rotation +2. 
The acetic ester of linalool constitutes about 40 per cent. of oil 
of bergamot, so it is not surprising that the odour of Lign-aloe 
has been thought to resemble that of bergamot. Lign-aloe oil 
also contains a small quantity of Geraniol. 
It is difficult to say whether other species of Bursera yield this 
oilor not. Poisson suggests that it is probably obtained also from 
Bursera Aloexylon, Engl. (Elaphrium Aloexylon, Schiede). 
The new Mexican Pharmacopeia (1884), p. 75, also gives 
Amyris linaloe, La Liave, which is a synonym of Bursera Aloexylon, 
Engl., as the source of the oil. Schlechtendal, however, in ‘ Lin- 
nea’ (1843), xvi. p. 303, remarks that this species has a fennel- 
like odour. 
Several other species of Bursera grow in the same district as 
B. Delpechiana, including B. bicolor, Engl., B. Schiedeana, Eng)., 
and B. jorullensis, Engl., but nothing appears to be known about 
the oil of these trees. Schlechtendal mentions (loc. cit.) that Ela- 
phrium glabrifolium (Bursera penicillata, Engl.) has a strong 
aromatic odour, and that Amyris ventricosa (Bursera fagaroides, 
Engl., var.) has an odour of caraways. 
* Ber. Deutsch. chem. Ges. 1891, xxiv. p. 207. 
