70 
PROFESSOR R. THRELFALL AND MR, J. H. D. BREARLEY 
Sulphur heated in a glycerine bath at rate of about ‘5° per minute. 
Table I.—Melting-point of Octahedral Sulphur. 
Number of experi¬ 
ment. 
Sulphur began to 
melt at 
Sulphur completely 
melted at 
° C. 
°C. 
1 
114-4 
116-86 
2 
119-86 
120-86 
3 
116-06 
116-06 
4 
118-46 
120-66 
Mean . . 
117-19 
118-61 
As Brodie has shown, octahedral sulphur heated beyond about 100° C. begins to 
turn into monoclinic sulphur. If the sulphur is in the state of fine powder, the 
change cannot be avoided even if the sulphur be heated “ for the shortest time 
between 100° and 114°’5 C.” As our sulphur was in small fragments, it was possible 
that the above discrepancies could be attributed to a more or less partial change 
having occurred. In order to test this, the glycerine bath was brought up to 
different temperatures near the melting-point before the sulphur was introduced. 
The results are as follow :—• 
Table II.—Melting-point of pure Octahedral Sulphur. 
Number of experi¬ 
ment. 
Initial temperature 
of bath. 
Sulphur began to 
melt at 
Sulphur entirely 
melted at 
Remarks. 
°C. 
°C. 
°C. 
5 
116 
116 
116 
Went at once 
6 
115-86 
115-86 
115-86 
Ditto 
7 
11506 
115-86 
115-86 
8 
108 
115-46 
116 
9 
106 
115-06 
116-06 
Mean (reject- ) 
ing No. 8) / 
• • 
115-69 
116-00 
These observations were made by Miss Florence Martin, a most careful observer, 
to whom our thanks are due. She recommends that Experiment No. 8 should be 
discarded, on the ground of the point of commencement not having been so sharply 
marked. 
It will be noticed that the above tables indicate two things : firstly, that on the 
whole the melting-point is lower when the sulphur is raised to it suddenly ; and 
secondly, that all the melting-points are considerably above those given by Brodie. 
The reason probably is to be found either in the fact that Brodie used imperfectly 
