16 Mr. William Sutherland on the 



The values added in brackets in the last table are reproduced 

 from Table VI. for purposes of comparison, and show that 

 according to our methods of calculation, for the inorganic 

 compounds the values of F come out about 1*1 times their 

 values as found in organic compounds (see also the values for 

 Br and I above). This is a satisfactory result so far as it 

 goes, but on the strength of it we will not proceed to a com- 

 parison between B and F in the last table, but will wait till 

 w r e have controlled these values by an independent calculation. 

 The data for other compounds in Table IX. are too few to 

 be worth discussing separately, but will be considered in 

 connexion with values by another method. The only data 

 for the surface-tension of liquid compounds at their solidi- 

 fying points known to me and not included in Table IX. 

 are those of Traube for some compounds of Na and K with 

 the fatty acids. These will now be briefly considered. 



Table XII. 



K. Na. 



rmate. 



Acetate. 



nate. 



Valerate. 



Stearate. 



77 



4-0 



23 



14 



1-4 



36 



53 



70 



104 



325 



53 



52 



5-0 



54 



14-3 



Formate. Acetate. 

 am 7'1 4-3 



M/p ... 44 81 



(MH)> .. 60 61 



These values of (M 2 /)* are exceptional, for they do not in- 

 crease by '9 for each addition of CH 2 to the acid radical : 

 with 4-2 for K and 3'1 for Na, also 2'9 for HCOO and -9 for 

 CH 2 , we can calculate the following values of (M 2 /)* for com- 

 parison with those just obtained from experiment — 



7-1 8-0 6-0 6-9 7-8 9-6 21-3. 



The reason for the discrepancies in these two sets of values 

 would have to be sought for by a special inquiry. 



2 (b). Second Method of determining (M 2 /)* for Inorganic 

 Compounds, namely by the Kinetic Theory of Solids. 



In " A Kinetic Theory of Solids " (Phil. Mag. ser. 5, xxxii.), 

 it was shown that, for a homogeneous isotropic solid composed 

 of molecules which can be regarded as spheres of diameter 

 E whose centres are at an average distance e from their nearest 

 neighbours, D being the average kinetic energy of each, 



- ^tr^r) = (3) 



3e 2 (e-E) 6e 

 E is also the distance apart of the centres of two when they 



