100 
of this carbon sulphide from the experiments described. A priori it 
does not even seem established that there is question here of one or 
more compounds of constant composition. Besides it seems possibie 
that a fixation by chemical forces has to do something with surface 
phenomena. In Lanemvir’s experiments *) on the fixation of oxygen 
by heated filament of carbon or tungsten one has to do with a very 
thin layer of oxygen, which is retained at the surface of the carbon 
or tungsten filament by chemical forces. 
Lowry and Hurertr®) have shown that amorphous carbon (in their 
case not entirely pure) can fix oxygen at 25° in another way than 
by absorption. Even at 180° this oxygen could not be pumped off 
from the carbon, at higher temperatures the oxygen split off as 
CO and CO,. Some years ago, RHEAD and Warerer*) have shown that 
oxygen can be fixed by amorphous carbon at temperatures between 250° 
and 500°, and that on heating of this carbon-oxygen complex 
CO and CO, is formed. In these researches it has been established 
beyond doubt that the fixation of oxygen to the carbon takes place 
by chemical forces. The quantity of oxygen fixed in this way 
in Lowry and Horerr’s experiments, was 1.7—3.75 of the weight 
of the carbon, a quantity which is, therefore, of the same order 
of magnitude as in the sulphur-carbon complexes. An analogy 
between these solid carbon-oxides and the carbon-sulphides described 
in this communication is undeniable. Whether these carbon sulphides 
also on still higher and more prolonged heating split off the sulphur 
as volatile carbon-sulphide compounds, would have to be decided 
by further experiments. 
It is possible that the sulphur atoms are bound by rest-valencies 
of the carbon atoms which have remained unsaturated after the 
combination of the carbon atoms to amorphous carbon. This rest- 
affinity will possibly not be the same for different preparations 
of amorphous carbon, but depend on the way in which the amorphous 
carbon has been obtained. 
Led by this idea I have made similar carbon sulphides starting 
from sulphur and from sugar-carbon, which had been purified by 
being heated successively in a current of chlorine, a current of 
hydrogen and in vacuum. In this way similar, but quan- 
litatively different, results were obtained. By heating of charcoal 
with sulphur first a large quantity of sulphuretted hydrogen was 
developed, and finally a carbonsulphide resulted containing 3,5 °/, 
1) Journ. Amer. Chem. Soc. 37, 1154 (1915) and 38, 2271 (1916). 
*) Journ Amer. Chem, Soc. 42. 1408 (1920). 
4) Journ. Chem. Soc. 101, 831 (1912), 103, 461. 
