THE CITRINE ODOURS. 81 
oil, and the liquid gently agitated so as to cause a slight undulatory 
movement. (Fluorescence was noticed by de Luca in rectified oil 
of Mandarine, either pure or dissolved in spirit, but he did not 
observe the phenomenon in the crude or unrectified oil, attributing 
its absence to the yellow colouring-matter *.) Neroli agitated with 
a saturated solution of sodium bisulphite assumes a very pure, 
intense, and permanent crimson tint. Examined in a tube of 100 
millim., it deviated the polarized ray 6 degrees to the right. The 
greater part distilled at 185° C., and the portion distilling at 195° 
being still colourless, of the same odour as the original oil, and 
still manifesting in a marked manner the violet inflorescence. The 
portion remaining in the retort was then mixed with rather more 
than its volume of 90 °/, alcohol, and the addition of a few drops 
of water caused no turbidity. A small quantity of crystallized 
Neroli camphor was seen floating on the surface of the liquid, 
which was obtained pure by redissolution in boiling alcohol. No 
camphor could be extracted from the rectified oil. Neroli camphor 
is neutral, inodorous, insipid, fusible at 55° C., and assumes a 
crystalline form on cooling from its solution in hot alcohol. The 
quantity of this product found in the sample was small, being only 
1 decigramme from 60 grammes of oil. The proportion of cam- 
phor in Neroli diminishes with the age of the oil.”? (The observers 
were unable to discover any substance of this nature in the oils of 
Petit-grain, of orange-peel, or of bergamot peel.) 
The great variations in the prices quoted for Neroli mdicate a 
great diversity of quality. The commercial oil is rarely pure, 
being adulterated with oil distilled from the leaves, and with a less 
odorous Neroli distilled from the sweet ‘ Portugal” orange. 
Common oil of Neroli often consists of 3 oil of Petit-grain (from 
the leaves), 4 oil of Bergamot rind, and 4 genuine Neroli. 
The usual time for beginning the collection of the orange-flower 
crop in the south of France is the last week in April, and the 
gathering lasts about a month or five weeks. The quantity gathered 
is at first rather small, but gradually increases, and after May 10 
reaches its full proportion. One of the principal centres of this 
industry is Vallaurie, the name being apparently derived from 
Vallum aurantii or its Provencal equivalent. There are fifteen 
distilleries of orange-flower in this town. The crop is said to 
* Comptes Rendus, Nov. 25, 1857. 
