For a complete digest of Faraday's discoveries in diamagnetism the reader is referred to the second edition of Dr. Noad's comprehensive and learned work entitled "A Manual of Electricity."
Coming always from the highest walks of philosophy to lower and "common things" one cannot help being reminded of the old-fashioned method of drawing up a sluggish fire, and the natural query is suggested whether the poker is to be considered as a weak magnet, and does influence and draw towards the fire a greater supply of magnetic oxygen gas? (Fig. 245.)
Fig. 245.
The interior of the optical box at the Polytechnic—looking towards the screen. The assistants are supposed to be showing the dissolving views.