
    (No. 6253
    Minnesota Mining and Manufacturing Company, Claimant, vs. State of Illinois, Department of Revenue, Respondent.
    
      Opinion filed November 9, 1971.
    
    Charles W. Ott, Attorney for Claimant.
    William J. Scott, Attorney General; Saul R. Wexler, Assistant Attorney General, for Respondent.
   Perlin, C.J.  