XXV11 





c 



30 00ODODO0O0Q0ODODOD 



























May give up Easter lectures and all other busi- 

 ness at Eoyal Institution. 



Gave up Friday evenings. 



G-ave up juvenile lectures. 



Gave up Mr. Brande's twelve morning lectures. 

 Closed three days in the week. ' 

 Declined reprinting ' Chemical Manipulation.' 

 Grave up many morning lectures. 

 Gave up the rest of professional business. 

 Gave up excise business. 

 Declined all dining-out invitations. 

 Gave up professional business in courts. 

 Declined Council business at Eoyal Society. 



m. 39 (1831). 



In this year the first series of * Experimental Researches in Electricity 5 

 was read to the Royal Society. It contained experiments (1) on the 

 Induction of Electric Currents, (2) on the Evolution of Electricity 

 from Magnetism, (3) on a new Electrical Condition of Matter, and on 

 Arago's Magnetic Phenomena. He had also in the Transactions a 

 paper on a peculiar class of acoustical figures, and on certain forms 

 assumed by groups of particles upon vibrating elastic surfaces. In the 

 Quarterly Journal of Science he had a paper on a peculiar class of 

 optical deceptions, which gave rise to the chromatrope. 



He gave five Friday discourses on a peculiar class of Optical Deceptions ; 

 on Oxalamide, discovered by M. Dumas ; on Light and Phosphorescence 

 (being an account of experiments recently made in the Royal Institution 

 by Mr. Pearsall, Chemical Assistant) ; on Trevelyan's recent Experiments 

 on the production of Sound during the conduction of Heat ; and on the 

 Arrangements assumed by Particles upon Vibrating Elastic Surfaces. 



He was elected an Honorary Member of the Imperial Academy of 

 Sciences, Petersburg. 



In a letter to his friend, Richard Phillips, he first complains of his 

 memory. " My memory gets worse and worse daily, I will not therefore 

 say I have not received your Pharmacopoeia." Three months later he thanks 

 him for the last edition of the Pharmacopoeia, and says, "I am busy just now 

 again on electro-magnetism, and think I have got hold of a good thing, 

 but can't say. It may be a weed instead of a fish that, after all my labour, 

 I may at last pull up. I think I know why metals are magnetic when in 

 motion, though not (generally) when at rest." 



Nov, 29. Two months later he again writes, and this time from 



