suitable temperature. As has already been observed it is possible 
that either a compound of S with S,Cl, is formed or else another 
sulphur modification. That, in this latter case, there can be no 
question of the formation of S, is shown readily from the following 
experiments. 
On heating S with S,Cl, we can obtain very concentrated sulphur 
solutions. If this were caused by the formation of 5,, this ought to 
have a great solubility, or the separation of S, ought to take place 
very slowly when, by heating, a concentrated solution of 5, has 
been obtained. Neither of these phenomena occur, however. If sulphur 
which, owing to heating and rapid cooling, contains a certain quantity 
of S, is brought into contact with SCI, a turbid liquid is formed 
immediately. This turbidity of S, is permanent at the ordinary tem- 
perature, but on warming for a few minutes at 100°— 110° it disappears. 
On cooling, however, the turbidity at once reappears. Hence, it is 
shown that the solution and subsequent separation of Sz is a process 
which takes place withou tappreciable retardation. At the temperature 
of the room, the solubility of S, is very trifling, for the experiment 
just described may be carried out with a very little 5,. Ata higher 
temperature the solubility is apparently fairly large. At 100°—110° 
an appreciable, rapid transformation of S, takes place, presumably 
into S;, for if the above experiment is repeated a few times, the 
turbidity of S,, finally, does not reappear. 
Not only in pure S,CI, but also in $,Cl, containing S$, the solubility 
of S, is but small, although the solubility of S, in S,Cl, is increased 
by addition of S,. For, on adding to S,Cl, which is turbid by 5, a 
large quantity of S;, the turbidity disappears, but only when very 
little S has been added. The possibility of the formation of 5, in 
considerable quantities in solution is therefore excluded. 
In order to ascertain what is formed from the 5; originally present, 
the proper way would be to determine the melting point line of the 
system St SCI, after heating. It appeared, however, that nothing 
else but rhombic sulphur or S,Cl, was separated. The newly formed 
product does not separate at all. As, moreover, no suitable chemical 
method could be found to separate the new product from the other, 
systematic determinations were carried out of the solubility of sulphur 
in mixtures that had been heated to a suitable temperature. From 
this it can also be shown whether a new modification or a compound 
has formed. 
The system S+8,Cl, must be treated as a ternary system, as 
besides S, and S,CI, a third kind of molecule is present. The com- 
position of a mixture that has been heated for a certain time must, 
