46 Mr. W. Sutherland on the Laws of Molecular Force. 



data ; nor have the transition cases between the simple 

 typical compounds and the organic series been worked out. 

 It is interesting to find in molecular force a new clue towards 

 the realization of the desire of chemists to trace out the 

 transition from the dualistic to the unitary type of compound. 

 The atomic parameters /3, 7, . . . p, a- . . ., relative values of 

 which have been given under the symbol F, which is the 

 part contributed by an atom to (M 2 Z) g , have been shown to 

 be related to the volumes of the atoms ; in the organic com- 

 pounds many atoms and radicals have F closely proportional 

 to the volume of the atom, and in the case of the halogens 

 this holds good also in the inorganic compounds. Denoting 

 the volume of an atom by B, the approximate relation is 

 B=10 F or 9 F, but for a compound acid radical of basicity 

 higher than one the relation becomes B = 9F/2 ; here again 

 is evidence of chemical influence on molecular force. In the 

 case of metallic atoms in their compounds, it has been 

 shown that F is not proportional to the volume of the atom, 

 and on passing on to the uncombined metals it is found 

 that F, which represents the atomic parameter, is in the 

 main families of metals approximately proportional both to 

 the square root of the volume of the atom and the square 

 root of the valency, and in the subfamilies is a simple 

 multiple of a number which is so proportional. On returning 

 to the metal atoms in the combined state, it was found that 

 the relation is F 2 = «B + 6 in each family, a and b being 

 constants characteristic of the family. The profound influence 

 of valency in the uncombined metals is again of deep chemical 

 interest, as is also the great difference in the law connecting 

 atomic parameter and volume from that holding amongst the 

 extreme non-metals. These are the main results ; amongst 

 subsidiary results may be mentioned a certain amount of con- 

 firmation given to the Kinetic Theory of Solids by its successful 

 application to the calculation of force parameters, successful 

 insomuch as its results are in harmony with those obtained 

 by a perfectly independent method. This confirmation is the 

 more useful because it applies to the extension of the theory 

 to compound solids, whereas in the original paper the metals 

 only were treated of. 

 Melbourne, August 1894. 



