336 BELL SYSTEM TECHNICAL JOURNAL 



adequate. It is the law governing angular momentum which imprints 

 upon these electron-families the characters which we recognize as the 

 properties distinctive of the elements. It seems strange indeed that 

 character should depend upon motion, and fixity upon the laws of 

 whirling things; but however strange it may seem, there is no doubt 

 about it. In the construction of houses the builder requires raw 

 material in the form of brick and stone and wood and steel; but he 

 requires also principles of architecture, whereby the raw materials 

 may be parceled oflf and integrated into the general design. In the 

 construction of the physical world, mass and charge fulfil the role of 

 raw materials, and the laws of angular momentum furnish the principles 

 of the architecture thereof. 



