2 Mr. William Sutherland on the 



applying to the serial compounds of carbon, and the other to 

 the simpler compounds such as those of inorganic chemistry. 

 The advantage of the empirical expression M 2 Z = 6S + *66S 2 

 was that it happened to lend itself to some of the transition 

 cases which occur between the two classes. But now it is 

 clearly our duty to set aside the empirical law, and confine 

 our attention to (M 2 Q* proportional to A?m. The following 

 is a brief statement of the order in which these further studies 

 will be taken, and of their results. 



1. Values of (M 2 iy in the carbon compounds, with deter- 

 mination of the parts contributed to them by various atoms 

 and radicals, and proof that in the non-metallic atoms these 

 parts are approximately proportional to the volumes of the 

 atoms. 



2. (a) and (b). Development of two methods of deter- 

 mining (M 2 /)* for inorganic compounds, especially compounds 

 of the metals, tabulation of the results of the methods, with 

 proof that valency controls the magnitude of molecular force 

 in these compounds. (For example, if RS n is a compound of 

 a metal R of valency n with n atoms of S, then (M 2 /)^ for 

 RS n is the sum of a value for R and n times a value for S, 

 all divided by the square root of n.) 



3. Determination of (M 2 /)* for the uncombined metals, with 

 proof that in the main chemical families (M. 2 iy for each atom 

 is proportional to the square root of the volume of the atom 

 and also to the square root of its valency. Relation between 

 the volumes of the metallic atoms in combination and the 

 parts contributed by them to (M 2 Z) 5 in their compounds. 



4. General summary of results, and analysis of molecular 

 attraction into the sum of atomic attractions, with general 

 statement of their laws. 



1. Values of (M 2 /)* in the Carbon Compounds. 



To begin with, the law of the Dynic Equivalents remains 

 unchanged, for the dynic equivalent of an atom being the 

 number of CH 2 groups which would contribute as much to 

 the value of M 2 Z for a molecule as the atom does, it remains 

 the same for (M 2 /)* as for M 2 Z. This will appear in all the 

 values of (M 2 /) 1 that follow. From Table XXV. of the Laws 

 of Molecular Force we get the following values of (M 2 Z)*ac A*m 

 for the paraffins :— 



C A- C 6 H 14« C 8 H 18 . C 10 H 22' 



3-8 7-7 9-5 11-2 



