Beier tek ARTICLES 
A MODIFICATION OF A JUNG-THOMA SLIDING 
MICROTOME FOR CUTTING WOOD 
(WITH ONE FIGURE) 
The object and knife carrying blocks are long and heavy. These have 
planed surfaces of contact with the running surfaces of the base, instead 
of being mounted on ivory bearings, as is the case in the Thoma instrument. 
When oiled, the blocks are held by capillarity so firmly to the tracks that 
the whole instrument can be suspended by either block without bre: aking 
the contact. In this way rigidity is secured and vibration eliminated, vs 
far as the running surfaces are concerned. The friction of running 8 
less than in the ordinary Thoma. 
The object clamp is mounted on a solid ball (1.25 inches diameter), 
in a tight socket. This ball can be revolved horizontally through 180° 
and vertically through about 45°. It has two orienting levers whose ax€° 
Botanical Gazette, vol. 50] [148 
wre 
