20 REPORT—1874. 
in : 5 Specific . 
Boiling-points Specific Ere Specific 
festtrcted). peavity.. ee dispersiot 
A 175-178 08508 0:5652 00397 
Boe. lS aL73 0°8622 0:5562 0:0413 
Cae eral (Lit 0:8373 0°5620 0:0414 
Dee. L75-L77 0:8555 0:5611 0-:0407 
KE. . 176-177 08682 0-5510 0-0391 
Reticit etal (oie 0°8455 0:5654 0-0406 
g G . 176-177 0:8577 0:5626 0:0420 
H 175-178 0°8534 05589 0-0404 
Each of these specimens yielded terephthalic acid (averaging 40 per cent.) 
free from all trace of isophthalic acid, together with acetic acid free from all 
trace of higher homologues, by the action of chromic acid liquor. 
The statements of Riban, that cymene is formed by the action of sulphuric 
acid on certain terpenes by the reaction 
C,,H,,+H,80,=2H,0+80,+C,,H 
10°14? 
have been verified ; nevertheless the opinions expressed by the reporter in 
last year’s Report that cymene may be isolated from certain hydrocarbons, 
e.g. oil of turpentine, by the polymerizing action of sulphuric acid have been 
found correct, it being found practicable to obtain a few per cents. of cymene 
from an old sample of turpentine-oil without any evolution of sulphur dioxide 
by careful manipulation. Orlowski also has recently obtained cymene from 
old oil of turpentine by continued fractional distillation, the mode of produc- 
tion of the cymene being probably first the absorption of oxygen and produc- 
tion of a camphor-isomeride like myristicol, or the analogous products obtained 
in small quantity by the action of chromic liquor on hesperidene and myris- 
ticene (British Association Report, 1872), and the subsequent breaking up of 
this product into water and cymene by continued distillation. 
2), .H,,+ 0,=20,.H,,0, 
C,,H,,0=H,0+C,,H 
107" 16 10~-14° 
Physical Properties of Essential-oil Constituents and Conclusions. 
The following values were obtained for some of the other constituents of 
the essential oils examined :— 
Terpenes. 
¥. E . Specifi 3 
Souris: Boiling-point Specific Rae ret Specific 
(corrected). gravity. energy dispersion. 
I. Citronellol and phosphorus } ,2 ,-° wee 94 
Scene ‘} 175-178 08484. «= -0:5570-——0-0271 
IT. Citronellol and zine chlo- 
mae Bea te 170-180 0°8375 0:5400 0:0285 
Oxidized substances. 
Absinthol 5% 0 oes. ek o-202 0:9128 0:4887 0:0234 
Cajeputol ; ... 5. Seaisieeenleb—l ago 0:9207 0:4916 0:0251 
Citronellol <. {ee 6 4200=205 0-870 0:5213 0:0289 
t © lew Mee lrerep er O-elled 0-890 0:-5176 0:0284 
5 ide Ries ake co—lOU) 0°887 0-5247 0-0301 
Neither of the two terpenes were perfectly pure, I. being admixed with 
