A. W. Eviell — Rotatory Polarization. 



381 



Co., Ltd. of Allegheny, Pa., ll'9 cm long, O506 cm in diameter, 

 with, carefully polished ends, perfectly transparent and show- 



Twist. 



Logarithm of Twist. 

 ing no trace of strain when examined between crossed Nicols. 

 Circular wood blocks were carefully fitted and glued around 

 the ends. These were fixed in the clamps of the apparatus 



