64 Scientific Intelligence. 
rate of relaxation of that strain which the light indicates. 
If the motion of the spatula in its own plane, instead of being 
the plane of polarization, is inclined 45° to it, no effect is observed, 
. : 
b 
the light, showing, as may be s 
nettle is not a true jelly, but consists of cells filled with fluid. 
time of relaxation.— Phil. Mag., xlvii, 390. 
with Fluorescent Eyepiece.—M 
angle. The fluorescent plate may be made of uranium glass, or 
of thin pieces of glass a short distance apart containing any fluores- 
cent liquid between them Two lines drawn at righ 
the glass take the place of cross-hairs. It is a good plan to inter- 
