442 Mrs. K. Stratton and Prof. J. R. Partington on 



second outer bath o£ paraffin-wax, kept as nearly as possible 

 at 120° C. ; the presence of both the solid monoclinic form 

 and liquid in the sulphur bath prevented variations in 

 temperature. 



A weighed amount of pure sulphur was then placed in the 

 inner vessel, and this placed in the sulphur bath after being 

 previously heated on a water bath for 2 hours. The temper- 

 ature of this gradually rose to 120° C. and was allowed to 

 remain at this temperature for at least half an hour. The 

 coil was then connected up and the sulphur fused. The coil 

 used in these experiments was a little different from those 

 used for phenol and benzophenone. It was thought that the 

 sulphur when heated might attack the ebonite, so that thick 

 mica was substituted, a flat piece, rectangular in shape, 

 1 inch long, f inch wide, and J inch thick, being used for 

 supporting the coil. 



Results. 



1st Experiment. — W = 47*7094 grms. ; C = l*43 amps.;; 

 R = 2*56 ohms ; £ = 5 mins. 40 sees. .*. L = 8"87 gram cal. 



2nd Experiment. — W = 46*0434 grms.,- = 1*38 amps.; 

 R = 2'56 ohms; t = 5 mins. 50 sees. .*. L = 8*82 gram cal. 



These results do not agree with the value for monoclinic 

 sulphur given by Wigand (Zeit.physikal. Chemie, lxiii. p. 273, 

 1908). viz. 



L = 10*4 grin, cal. per grin, (monoclinic). 



The sulphur experiments, it is also hoped, may be repeated. 

 An improvement would be to convert the sulphur mainly to 

 the monoclinic form before the experiment. It may be 

 noted, however, that the presence of unconverted rhombic 

 sulphur would, according to Wigand's data, have raised the 

 value of L, which in our experiments is lower than that 

 found by Wigand. By using smaller quantities of material 

 we think it will be possible to determine the latent heat of 

 rhombic sulphur. Any error in our method would appear 

 to make a high result probable, whereas our values are some- 

 what loicer than those of previous experimenters when any 

 appreciable difference exists. 



Summary of Experimental Results: 



The results so far obtained may be summarized as follows: — 

 The latent heats of fusion in gram calories per gram of 

 substance are : benzophenone 21*70 ; phenol 29 - 06 ; mono- 

 clinic sulphur 8*85. The probable accuracy is greatest for 

 the benzophenone. 



