446 



Latent Heats of Fus 



'that complicated molecules, in which the possibility of intra- 

 molecular vibration is greater (as is known from the values 

 of ry = C p /G v in the case of gases and vapours), have high 

 -values of n. It is proposed to return to this question in a 

 further communication. 



Table I. 



Substance. 



I M. 



Hydrogen > 2 



Nitrogen 28 



Chlorine [ 70 



Mercury I 200 



Bromine ! 159*8 



Todine ; 254 



Potassium 39 



Sodium , I 23 



Lead | 207 



Sodium hydroxide. j 40 

 Potassium fluoride.; 58 

 Silver bromide ...I 187 



Lead chloride j 178 



Barium chloride.. ; 208*3 



Acetic acid : ! 60*03 



Phenol ; 94 



Benzene I 78 



Benzophenone I 182 



Naphthalene I 128*1 



ML 



obs. 



16 



192 



814 



550 



1293 



1487 



574 



626 



1118 



1610 



6275 



2370 



5150 



5581 



2641 



2735 



2340 



3950 



4483*5 



14 

 62*5 



169-5 



234-3 



265-7 



386*5 



336-5 



371 



600 



633 

 1133 



703 



764 

 1232 



289-7 



313 



278-5 



321 



353 



vX 



io- 15 



i 2-669 

 1-402 

 1-578 

 1361 

 1*069 

 1*023 

 253 

 2921 

 1-99 

 4*601 

 4-737 

 1-92 

 1*40 

 1*900 

 1-757 

 1-261 

 1-306 

 0-7447 

 1064 





Fy- 



ML 





1 



zTm * 



T ' 



n. 

 4-6 



! 129-8 



0*0247 



114 



i 68*17 



0645 



307 



4-8 



76*72 



0-835 



4-790 



5-7 



61*19 



0-89 



2-34 



2-6 



51*95 



0*99 



4-879 



5 



49-75 



0-944 



3 84 



4 



123 



0-875 



1*71 



1*9 



142*1 



0*86 



1-68 



1-9 



96*8 



0934 



1-86 



20 



223*8 



0-868 



2-543 



29 



230-3 



0-92 



5-525 



6*0 



93*4 



945 



1-89 



20 



65*1 



0-955 



667 



7-0 



92*39 



0-96 



4-471 



4-7 



85*43 



0-888 



10-91 



12-3 



61*31 



923 



7*49 



8*1 



63-5 



0-909 



8-5 



94 



36*20 



0-9515 



12-28 



12-9 



51-71 



0-941 



12-70 



13-5 



Summary* 



The latent heats of fusion of benzophenone (21*70 g. cal. 

 per g ) ; phenol (29*06 g. cal. per g.) ; and monoclinic 

 sulphur (8*85 g. cal. per g.) have been determined by electrical 

 'heating at the melting-point. A theory of fusion from the 

 point of view of the quantum theory, with the use of Debye's 

 formula for the energy, has been suggested. In some cases 

 the existence of intramolecular vibrations, as well as rotations, 

 is shown to be probable in the case of liquid molecules. 



The authors desire to .express their thanks to the Chemical 

 ^Society for a grant which largely covered the expense of the 

 investigation. 



East London College, 



University of London. 



