94 
at 400° showed 98,35 °/, C. 0,75°/, H., and 0,30°/, ash. After one 
hour heating at 660—660° at 2 mm.: 98,68°/, carbon, 0,53 °/, 
hydrogen, 0,30°/, ash. When the rest is estimated as oxygen, and 
when this content of oxygen is attributed to absorbed water, which 
has not been removed in spite of the heating at 600° in vacuum, 
the dried preparation has the following composition: ash 0,30 °/,, 
carbon 98,68 °/,, absorbed water 0,49 °/,, hydrogen (chemically 
bound) 0,48 °/,. 
Even after prolonged heating at 1000° in vacuum a small quantity 
of hydrogen is retained in this preparation. This hydrogen content 
lies, however, near the limit of the errors of the analysis. Apart 
from the ash-content, the preparation consists, therefore, practically 
of amorphous carbon. The ash almost entirely dissolved in hydro- 
chlorie acid, and contained but very little iron-oxide. 
The following experiments were made with this amorphous carbon 
K,: 24 grammes of K, were mixed with 8 grammes of pure sulphur; 
the mixture was placed in a porcelain tube, which was shoved 
horizontally into an oven heated at 510° C. The temperature of the 
oven was raised in an hour to 760°, and in the following 90 minutes 
to 975°. From 600° to the end of the experiment there developed 
some sulphuretted hydrogen. After cooling much sulphur was found 
in the colder part of the tube, which had been condensed there. 
The black carbon-like mass was again placed in a porcelain tube, 
and this was slowly beated in a vertical oven. At 800° very little 
sulphuretted hydrogen began to develop; the temperature was 
carried up to 1000° in two hours, and kept at 1000° for half an 
hour, then the H,S-generation had ceased and the heating was 
discontinued. A sulphur determination in the carbon-like powder 
showed: 1,98 °/, S. 
16 grammes of P, were extracted for a long time with boiling 
toluene; after evaporation of the toluene no sulphur remained behind. 
2,03°/, was found for the sulphur content of the extracted product. 
Hence extraction with toluene does not reduce the sulphur content 
of P,. Extraction with carbon disulphide did not lead to the purpose, 
as it appeared impossible to remove the last rests of carbon disulphide 
from the extracted product. 
I then tried whether through heating in vacuum, in which the 
receiver was cooled with liquid air to condense gaseous compounds 
that might possibly be formed, a sulphurous substance could be 
isolated from this preparation. It appeared, however, in several 
experiments that even prolonged heating in vacuum reduced the 
sulphur-content of P, hardly perceptibly; hence a volatile sulphur 
