nnd. d 
Notes ON SCIENTIFIC RESEARCH. eek 123 
oa 
- polyterpenes. At nipher erineratutes allen or larger quantities of gas were developed, 
- according to the kind of catalyst used. 
The pinene vapours led over copper at 500°, yielded a gas burning with a luminous 
ao Say and rich in hydrogen and ethylene hydrocarbons, together with a greenish liquid. 
‘ 
At 
In the distillate obtained at 600 to 630° were found benzene in small quantities, also 
toluene, m-xylene (b. p. 139°, d 0.871), zsoprene (?) or piperylene (%), hexenes, terpenes, 
-ethylene- and diethylene hydrocarbons, and above all, in the chief fraction, cymene 
(b. p. 175°), together with cumene, methylethylbenzene, and terpenes isomeric with 
_ pinene (b. p. 170 and over 180°). Altogether about 31 per cent. of aromatic hydrocarbons, 
capable of being’ isolated as nitro. compounds, were obtained from the pinene. 
Since nickel had a hydrogenating effect, the reaction product obtained at about — 
600° contained more saturated hydrocarbons; in the fraction 150 to 180°, a terpane 
was found together with cymene. Whilst cobalt in its action at 600° resembled partly 
the copper and partly the nickel, the same results were obtained with iron as with nickel. 
Porvhone: — The Peni product of Concentrated’ Sulplunic - acid on turpentine oil 
—the so-called terebene — has belonged since 1890 to the preparations of the American 
_ -pharmacopeeia, and since 1890 to those of the British pharmacopceia. In the current 
_ editions of both books the fixed constants of terebene are given —the boiling point, 
“specific gravity. and the specific rotatory power). In very few cases, according to 
B. F. Howard *), does the terebene prepared according to rule coes with these constants, 
; since the raw material is seldom the. same. 
Howard reports that during the years 1913 to 1919 the American turpentine oil 
used for the preparation of terebene had continually varying constants. The specific. 
rotatory power especially varied between -+-18 and — 30°. Hence it is explainable, 
that the terebenes in most cases were also obtained with various specific rotatory powers. 
By reason of his investigations and observations Howard concludés that the 
decisive test for the purity of terebene is the boiling point alone— not the specific 
rotatory power and the specific gravity. The data of the pharmacopoeia ought there- 
fore to be modified as follows. 
“Description: —Terebene is a mixture ai dipentene and other hydrocarbons, ob- 
2 : ~ tained by shaking up turpentine oil with sufficient quantities of sulphuric acid gradually 
_ - added, till the reaction product, after steam distillation, has the boiling point given below. 
Criterion and testing: —A colourless liquid, pleasant odour, aromatic taste similar 
to that of turpentine, specific gravity 0.854 to 0.862; soluble in 5 parts 90 per cent. 
alcohol; the boiling point, particularly, 165 to 185° (below 160° only 5 per cent. 
of the preparation, at the most, should boil) leaving behind a small amount of a 
thick fluid residue; absence of rosin. Data on optical rotatory powers ought not 
to be required.” _ 1 
Camphene.— G. Langlois?) has published exhaustive researches on the isomerism 
- in the camphene series. In order to name the numerous camphene derivatives he 
designates the radicles derivable from camphenilane CoHie (1), viz.,.CoHis (Il) and 
_CsHy (Ill) as camphenilene*), and camphenilidene, respectively. According to. this, 
- camphene (IV) might even be called camphenilidene-6-methane. For the products of 
1) Cf. Report October 1905, 78; October 1915, 49; 1918, 58. — %) Pharmaceutical Journal 103 (1919), 
~ 76. — #) Annal. de Chim. 12 (1919), 193 to 363. According to kindly forwarded reprint. — +‘) According to 
Bs 
by Moycho and Zienkowski. Liebig’s Annalen 340 (1905), 53 
customary nomenclature, the name “camphenilene” is given to the hydrocarbon CyHy, which was obtained 
f 
Be "i, A “7 
