ia EP ee SP TEE ht 
¥ Sey 4 a; on ee “a Pig) ele 9 (te 
7 CPG ( Ve, ay 75 a ns Ly s ~ 4 
© we Rave in B. Valea teins or B. aiphatetin liquefaciens a valuable reagent for | 
testing the purity of naphthene hydrocarbons. Further, since even traces of admixed 
“hydrocarbons were quantitatively temoved from naphthene, the bacteria render it possible 
. SH prepare the last-named in a ‘pure state. Tausz found on. this ‘occasion that the © 
eer prepared according to Sabatier were not pure, on account of the presence 
wi aliphatic hydrocarbons. , ; | 
en The Tausz method up to the Bresent Hee been apilied to Hactions of pressure 
a distillates of artificial and natural lubricating oils, from which pure naphthene hydro- © 
Be carbons could be isolated. Also in a fraction of a polymerisation product of amylene _ 
= the absence of naphthenes could be proved, and in a fraction of Mumaman petroleum Ops 
B= - the absence of paraffin hydrocarbons. ch 
2 oe ee Sea of the absence of terpene hjdeseartone m are petroleum oils, —In addition to 
the naturally occurring terpenes, also those unsaturated hydrocarbons | obtainable fronk-) 
- terpene derivatives, or synthetically, are assigned to the group of the terpene hydro- 
% m carbons. All these hydrocarbons are distinguished by great chemical activity; mercury 
g salts such as mercuric chloride or mercuric acetate dissolved in methyl alcohol or 3 
fs water react at ordinary temperatures with all terpenic compounds, but not with other 
3 _ hydrocarbons. The earlier experiments instituted by Balbiano*) on the behaviour of 
_ terpene hydrocarbons with mercury acetate have again been taken up by). Tausz and ES 
H. Wolf?), but: they could only partly confirm his results. | Fhe hes 
4 _ By reason of his - investigations Tausz divides. the hydrocarbons into 4 groups. 
a To Group 1 belong those hydrocarbons which with alcoholic solutions of mercury 
acetate give mercury salts at ordinary temperature. These hydrocarbons which form | 
= _ their ‘mercury. ‘compounds by. substitution and addition of mercury salt and alcohol 
contain an active hydrogen atom joined to a doubly bound carbon atom. The hydro- 
carbons’ of Group 2 were only oxidised by an aqueous solution of mercury acetate at — 
: ordinary temperature. Group 3 comprises the. aromatic hydrocarbons, which still 
aS contain a free hydrogen atom in the nucleus, and which form their mercury salts by 
3 
rh 
substitution only, without an additive reaction, at a temperature of over 100°. To 
Group 4 belong the unsaturated compounds which heither form Se: salts, nor are 
| oxidised by mercury compounds. | 
The fact that all the terpene hydrocarbons investigated. by him, react with mercuric 
“acetate solution, and hence belong either to group 1 or group 2, has been applied — 
by Tausz to test raw petroleums for the presence of terpenes. Up to now it has only 
been proved that ethylene occurs in the mineral oil gas of Pechelbronn, hence that » 
_ the first member of the olefine series is present in petroleum. There is numerous but — 
& mutually contradictory information in the literature on the occurrence of terpene-like 
hydrocarbons in mineral oils. Tausz has elaborated ie folowing pragess fe prove 
the presence of terpenes in petroleum oils:— » 
se 7 g. mercury acetate are dissolved in 75 cc. methyl alcohol, and added to the 
. vacuum distillate (1 litre) of the mineral oil contained in a separating funnel of 3 litres 
i * _ Capacity, and the whole shaken up for 10 minutes. Two layers are present in the 
vacuum distillate; the lower is methyl alcohol and water, and must contain the terpene- 
= mercury compound, if present. The water- -methyl-alcohol layer is run out; the upper 
@ _layer is washed with methyl alcohol; the methyl alcohol is again run out and added 
_ to the former. The combined liquids are distilled in vacuo. The residue is tested 
for the terpene mercury compound. a j 
bib pF 1) Cf. Report April 1906, 100. — » Zeitschr. f, angew. Chem. 32 (1919), 1. 233, 
ao fe 
