Section 101. Limitation of powers

Nothing  in this article shall be so
  construed as to permit any such corporation to engage in manufacture  or
  production,  except for its own use, of power, heat, light, supplies and
  equipment or  to  carry  on  the  business  of  generating,  selling  or
  distributing  electricity for light, heat or power, nor shall the right,
  operation and use of such privileges be extended beyond the  streets  or
  marginal  streets bounding or occupied by the property owned or operated
  by such corporation. No railroad  corporation,  and  no  corporation  or
  joint-stock  association  engaged  in  carrying  on an express business,
  shall either directly or indirectly, or through the medium of a  holding
  company  or  otherwise,  purchase,  acquire  or hold, any stock, bond or
  evidence of indebtedness issued by any such corporation.