xlvii 



torially or across the magnetic lines of force, i. e. east and west in respect 

 of the north and south poles. If it be moved from this position it returns 

 to it, and this continues as long as the magnetic force is in action. This 

 effect is the result of a still simpler action of the magnet on the bar than 

 what appears by the experiment, and which may be obtained at a single 

 magnetic pole. For if a cubical or rounded piece of the glass be suspended 

 by a fine thread 6 or 8 feet long, and allowed to hang very near a strong 

 magneto-electric pole (not as yet made active), then, on rendering the pole 

 magnetic, the glass will be repelled until the magnetism ceases. This 

 effect and power I have worked out through a great number of its forms and 

 strange consequences, and they will occupy two series of the * Experimental 

 Researches.' It belongs to all matter (not magnetic as iron) without excep- 

 tion ; so that every substance belongs to one or the other class of magnetic 

 or diamagnetic bodies. The law of action in its simplest form is that such 

 matter tends to go from strong to weak points of magnetic force, and in 

 doing this the substance will go in either direction along the magnetic 

 curves, or in either direction across them. It is curious that amongst the 

 metals are found bodies possessing this property in as high a degree as 

 perhaps any other substance ; in fact I do not know at present whether 

 heavy glass, or bismuth, or phosphorus is the most striking in this 

 respect." 



In July he went with Mrs. Faraday and Mr. G. Barnard to France for 

 three weeks, partly to inspect the lighthouses at Fecamp, Havre, Harfleur, 

 and Cap de la Haye. His chief object was to be received into the Academy. 

 A.t the same time he gained all the information he could regarding French 

 lighthouses from M. H. Le Ponte and M. Fresnel. M. Dumas was his 

 most constant companion in his visits to Chevreul, Milne-Edwards, Biot, 

 Arago, the Well of Grenelle, and the water- works at Chaillot. On the 30th 

 of July he went to the Institute. " Many of the members were gone out of 

 town, but all that were there received me very kindly. I was glad to see 

 Thenard, Dupuis, Flourens, Biot, Dumas of course, and Arago, Elie de 

 Beaumont, Poinsot, Babinet, and a great many others whose names and 

 faces sadly embarrassed my poor head and memory. Chatting together, 

 Arago told me he was my senior, being born in 1786, and consequently 59 

 years of age." 



He finishes his journal thus : — " We left George at the London Bridge 

 Station ; thanks be to him for all his kind care and attention on the journey, 

 which is better worth remembering than anything else of all that which 

 occurred in it." 



He was made Corresponding Member of the National Institute, Wash- 

 ington, and of the Societe d'Encouragement, Paris. 



Ml. 54 (1846). 



Early in the year he gave a Friday discourse on the relation of Magnetism 

 and Light, and another on the Magnetic Condition of Matter, and, later in 



