Primary Laws. 79 



Section 2. Second Lata : Dual or Sexual- Material- 

 Selection : 



Definition : Like classes of atoms repel, and unlike 

 classes of atoms automatically attract each other 

 in order to effect production. 



From the dual classification of the elements into 

 metallic and non-metallic, nature, in all her ramifica- 

 tions, virtually becomes a vast household funda- 

 mentally grouped into seventy or more reciprocating 

 families. Fourteen or fifteen of these we may call 

 females (non-metallic), and the other fifty or more, 

 males (metallic). The conjugation of this fertile flux 

 has thus not only evolved the present variety of 

 natural products on the earth, but new products and 

 new varieties in ever increasing complexity must 

 continue to evolve so long as season succeeds season, 

 and the sun rises and sets. 



Confirmation of this sexual interaction is over- 

 whelming, for all observation and experiment in every 

 department of chemistry and in every domain of 

 nature prove that a mixture or compound of elements 

 may be prepared, but no veritable production differing 

 essential'y in appearance and properties from the 

 combining elements can be evolved without the union 

 of both metallic and non-metallic elements. For 

 example, common salt contains sodium (metallic) and 

 chlorine (non-metallic). 



Washing soda : — Sodium, with carbon and oxygen. 



Saltpetre : — Potassium and hydrogen, with nitrogen 

 and oxygen. 



