HARVARD UNIVERSITY 
DEPARTMENT OF CHEMISTRY 
12 Oxford Street, Cambridge, Massachusetts 02138 
.it 
M 'f . ' , 
t *r~* 
- : a — .ok ,*<&>+' 
„ 71 (1 - • 
V ' .V Mtf 
/ 
^ sr-* > ^ 
a*4 &**,#■** 
(U ^ 
[ 643 ] 
