CHEMICAL CONSTITUTION ETC. OF ESSENTIAL OILS. 19 
heating, forming hydrochloric acid, a terpene boiling between 168° and 173° 
and polymerides of higher boiling-point, the reactions being 
3 C,,H,,0+ PCl,= HCl+ POCI,+0,,H,,Cl 
an 
C,,H,,Cl=HCl+ 0,,H,,. 
III. Or or Caserut,—The “ cajeputene hydrate ” of Schmidt (the “ caje- 
putol ” of Gladstone) was approximately isolated from resinous higher boiling 
substances simultaneously present in the oil by fractional distillation, and 
boiled between 176° and 179°, or more than 30° lower than the isomeric 
substance from citronella-oil ; like its isomeride, it combined with two equi- 
valents of bromine, evolving much heat, and forming a dibromide splitting up 
by heat into hydrobromic acid, water, and cymene, thus 
C,,H,,Br,0=2HBr+H,0+40,,H,,- 
The yield of cymene, however, was much greater with the cajeputol dibro- 
mide than with the citronella product, 100 parts of C,,H,,O from cajeputol 
yielding about 67 parts of cymene, and 100 of that from citronella Jess than 
half as much. 
With phosphorus pentasulphide cajeputol behaves just as its isomeride, 
forming first a terpene and then cymene, the elements of water being first 
abstracted, and then two equivalents of hydrogen removed. 
TY. Acrron or PoospHorvs PEnrasuLPHipE on TERPENES.—In order to prove 
that the cymene formed when pentasulphide of phosphorus acts on the pro- 
ducts C,,H,,O from citronella and cajeput oils is really produced from a terpene 
first generated, the action of phosphorus pentasulphide on other terpenes was 
examined, oil of turpentine (boiling at 159°) and hesperidene (boiling at 178°) 
being chosen as being near the extremes of the range of boiling-points of the 
terpenes as a class. In each case most of the hydrocarbon was converted 
into a resinous mass; torrents of sulphuretted hydrogen were evolved, and 
some cymene formed, the yield being about 30 per cent. with oil of turpen- 
tine, and 40 per cent. with hesperidene; in these cases evidently the cymene 
is formed by the reaction 
Ce +S= HS ste C,.H,,. 
In each case a trace of cymyl-sulphhydrate appeared to be formed. 
_ Y. Examryarton oF vARIous Crmpnes.—The cymenes obtained as above 
described were carefully examined in the way detailed in last year’s Report ; 
all seemed to be identical with each other and with each of the eight kinds 
of cymene formerly examined as described in that Report. The following 
numerical values were obtained :— 
A Cymene from absinthol and zinc chloride. 
a vs Ns and phosphorus pentasulphide. 
citronellol dibromide."§ © © - - 
Fe a m and pentasulphide of phosphorus. 
cajeputol dibromide. ye ree 
re ? » and pentasulphide of phosphorus. 
hesperidene and pentasulphide of phosphorus. 
oil of turpentine and pentasulphide of phosphorus, 
; C4 
2 2? 
”? 
HPotbyaw 
