1259 



Page 1075, line 8 fi-om bottom: For "wliicli could only be l)ound 

 by 0,0015 mg Si" read "wliieli could be bound l)y only 

 0,0015 mg Si". 



Page 1076, line 15: For "Na,!)" read "Na,0". 



Page 1076, line 23: For "that intensively emits electrons" read 

 "that does not or very little emit electrons". 



Page 1076, line 2 from bottom: For "in" read "on". 



Page 1077, line 2: For "colour" read "deposit". 



Page 1077, lines 7 and 6 from bottom: For "oidy quantities of the 

 order of magnitude of 0,001 mg Si show a detectable 

 activity" read "quantities of the order of magnitude 

 0,001 mg Si show already a detectable activity". 



