For demonstrating Brownian motion. Designed for use with
a microscope. A short cylindrical cell, close by a cover glass,
is held vertically in an opaque channel. 90 x 90 x 30 mm.
Illumination is by an integral filament bulb and cylindrical
glass lens. The cell enables Brownain motion to be observed
for at least 15 minutes after charging the cell with smoke.
/ fitted 4 mm socket terminals for connection 12 V supply.