93 
Powerr ') communicates the result of further researches. In this the 
behaviour of the sulphur compounds during coking is examined in 
details for different kinds of coal, in which the already mentioned 
results were confirmed and extended. 
It seems, however, to me that also questions of more general 
importance present themselves in connection with these reactions. 
In what way is this compound of sulphur and carbon formed, in 
which evidently a complex is formed that is very resistent with 
regard to heating? A preliminary experiment had already taught 
me that through quick heating of sugar carbon with sulphur a 
carbon-like sulphurous substance is obtained, which can be made 
red-hot without losing its sulphur content. Accordingly the mutual 
behaviour of two simple substances as sulphur and carbon is not 
yet known in detail. Hence | have begun an investigation purposing 
to examine the behaviour of amorphous carbon and sulphur on 
heating, and study more closely the products that arise from these 
two components. Though this investigation is not yet entirely com- 
pleted, I feel obliged in view of PoweLr’s publications, to commu- 
nicate already now the experiments carried out by me. 
$ 2. In order to obtain reproducible results, it was desirable to 
experiment with an amorphous carbon as pure as possible, which 
was obtained in a well-defined way. 
Finely powdered sugar-carbon obtained through moderate heating 
of sugar, was extracted with boiling hydrochloric acid, after which 
the ash-content was 0.30°/,. Through extraction with hydrofluoric 
acid this ash-content is only little diminished. This carbon was heated 
at 900—1000° in a porcelain tube for 7 hours. The generated gases 
were pumped off by means of an oil-pump, in a vacuum of + 1,7 
mm. This preparation was analysed, and then again heated at 
970—1020° for three hours in a vacuum of 0.6 mm.; during the 
last hour of this heating experiment there was no generation of 
gases any more. The evacuation was continued during the cooling. 
The analysis of this carbon was performed as follows: a weighed 
quantity of substance was heated in a porcelain boat at 400—450° 
and 1 mm. for one hour; after having been cooled in vacuum, the 
boat was quickly placed in a weighing bottle, reweighed, and at 
once conveyed to the combustion tube. Such amorphous carbon is 
very hygroscopic; the content of absorbed water determined in this 
way, was 1.83 °/,. The analysis of this carbon dried in vacuum 
1) Journ. Ind. and Engin. Chem. 12, p. 1069, 1077 (1920). 
