322 F. B. GUTHRIE. 



ionally tetravalent (in S01 4 ), and hexavalent (SP 6 ). The 

 molecule of sulphur may therefore be represented by the 

 graphic formula : — 



S 



If now we indicate direction in the various bonds and 

 replace the straight lines by arrows showing the direction 

 in which the electrons are projected towards the neighbour- 

 ing atom, we shall be able to produce a large number of 

 possible figures representing the structure of the different 

 molecules formed by variations in the valency direction. 



It is fair to assume that the transference of corpuscles 

 takes place only between the atoms within the molecule 

 and that corpuscles are not discharged beyond the molecule, 

 which would result in its disintegration. It is further 

 demonstrable that if a greater number of electrons travel 

 in the one direction than in the other, (except in the case 

 in which they all travel in the same direction) the result 

 is unsymmetrical, and presumably unstable. We thus 

 reduce the number of possible figures to about forty, of 

 which only four are symmetrical, namely : — 



1. In which all the corpuscles travel in the same direc- 



tion, represented by the formula (a a a a a a a a). 



2. In which each alternate bond represents a corpuscle 



travelling in opposite directions, represented by 

 the formula (ab ab ab ab). 



3. In which a pair of neighbouring bonds represents cor- 



puscles travelling in one direction (a) alternating 

 with a pair travelling in the opposite direction (b) 

 represented by the formula (aa bb aa bb). 



