1901-:.] Prof. Alexander Smith on Amorphous Sulphur. 299 
Amorphous Sulphur and its Relation to the Freezing 
Point of Liquid Sulphur. By Professor Alexander 
Smith, Ph.D., D.Sc. 
(Read June 2, 1902.) 
Rhombic and monoclinic sulphur are two physical states of the 
element with a transition point at 96°. The relation of amorphous 
sulphur to liquid sulphur is entirely different. The former is 
produced by heating liquid sulphur, and is found in increasing 
proportion as the temperature is raised. At 448° it reaches about 
forty per cent. As the temperature falls, the proportion of 
amorphous sulphur recedes, although sudden cooling arrests the 
regression, and furnishes solid specimens containing the larger 
proportions proper to higher temperatures. The case seems to 
be one of chemical equilibrium, S (liquid) S (amorphous), in 
which the action, as written, is endothermal. 
If this interpretation is correct, the variability of the freezing 
temperature of sulphur, observed by Brodie, Gernez, Schaum, and 
others, may be due simply to depression of the freezing point by 
varying proportions of amorphous sulphur, the latter acting as a 
foreign dissolved body. Two series of experiments, in which the 
freezing points of specimens of previously heated liquid sulphur 
were accurately determined by means of a Beckmann thermometer 
and suitable apparatus, confirmed this view. As soon as the 
temperature had been read, the mass was poured into a cold dish, 
and on the following day was pulverised and extracted with 
carbon disulphide. A correction was made for the solubility of 
the amorphous sulphur after separate investigation of this point. 
The following table gives one series, the quantities of amorphous 
sulphur in the second column being those associated with 100 gr. 
of soluble sulphur : — 
