330 THE KOYAL INSTITUTION. [CHAP. VI. 



attention even to the common duties and affections of life. 

 . . . Your correspondence is to me a real source of pleasure, 

 and, believe me, I would suffer no opportunity to escape of 

 making it more frequent and regular. 



My labours in the theatre of the Royal Institution have 

 been more successful than I could have hoped from the 

 nature of them. In lectures the effect produced upon the 

 mind is generally transitory ; for the most part they amuse 

 rather than instruct, and stimulate to inquiry rather than 

 give information. My audience has often amounted to four 

 or five hundred and upwards, and amongst them some 

 promise to become permanently attached to chemistry. 

 This science is much the fashion of the day. 



I mentioned to you in a former letter the great powers 

 of galvanism in effecting the combustion of metals. I have 

 lately had constructed for the laboratory of the Institution 

 a battery of immense size ; it consists of four hundred plates 

 of five inches in diameter and forty of a foot in diameter. 



I am now examining the agencies of it upon certain 

 substances that have not as yet been decomposed. 



Have you seen the theory of my colleague, Dr. Young, on 

 the undulations of an ethereal medium as the cause of 

 light ? It is not likely to be a popular hypothesis after 

 what has been said by Newton concerning it. He would 

 be very much flattered if you could offer any observations 

 upon it, whether for or against it. 



We are publishing at the Royal Institution a ' Journal 

 of Science,' which contains chiefly abridged accounts of 

 what is going on in different parts of Europe, with some 

 original papers ; and, in hopes that its diffusion may become 

 more general, we have fixed its price at one shilling. 



I am beginning to think of my course of lectures for the 

 winter. In addition to the common course of the Institu- 

 tion, I have to deliver a few lectures on Vegetable Sub- 



