44 



NOMOS. 



ends by restoring the original molecular arrangement 

 of the platinum and copper, and by isolating the 

 positive elements of the two zinc molecules whose 

 negative elements have gone to the formation of 

 the chloride of zinc molecules. The causes of these 

 changes are the same as those which operated pre- 

 viously. Thus : 



Fig. 9. 



Fig. 10. 



All change is now at an end, because the mole- 

 cules of hydrochloric acid and zinc are both decom- 

 posed. If more of these molecules had been present, 

 these changes would have been repeated, a zinc 

 positive element being left behind for every hydro- 

 gen element which escapes as gas, and for every 

 chloride of zinc molecule which is precipitated. 

 These changes are simply repeated, and it would 

 only confuse matters by following them further. 

 Nor are the changes really different when other 

 exciting fluids are substituted for hydrochloric acid, 



