LIFE AND LETTERS OF FAR AD AT. 303 
ators; they are also extremely bad conductors. The 
moment we pass from the metals to their compounds we 
pass from good conductors to bad ones, and from bad 
radiators to good ones. Water, among liquids, is probably 
the worst conductor; it is the best radiator. Silver, among 
solids, is the best conductor; it is the worst radiator. The 
excellent researches of MM. de la Provostaye and Desains 
furnish a striking illustration of what I am inclined to 
regard as a natural law that those atoms which transfer 
the greatest amount of motion to the ether, or, in other 
words, radiate most powerfully, are the least competent to 
communicate motion to each other, or, in other words, to 
propagate by conduction readily. 
CHAPTER XVIII. 
LIFE AND LETTERS OF FARADAY. 
1870. 
UNDERTAKEN and executed in a reverent and loving 
spirit, the work of Dr. Bence Jones makes Faraday the 
virtual writer of his own life. Everybody now knows the 
story of the philosopher's birth; that his father was a 
smith; that he was born at Newingtou Butts in 1791; that 
he ran along the London pavements, a bright-eyed errand 
boy, with a load of brown curls upon his head and a 
packet of newspapers under his arm; that the lad's master 
was a bookseller and bookbinder a kindly man, who 
became attached to the little fellow, and in due time made 
him his apprentice without fee; that during his apprentice- 
ship he found his appetite for knowledge provoked and 
strengthened by the books he stitched and covered. Thus 
he grew in wisdom and stature to his year of legal manhood, 
when he appears in the volumes before us as a writer of 
letters, which reveal his occupation, acquirements, and 
tone of mind. His correspondent was Mr. Abbott, a mem- 
ber of the Society of Friends, who, with a forecast of his 
correspondent's greatness, preserved his letters and pro- 
duced them at the proper time. 
In later years Faraday always carried in his pocket a 
blank card, on which he jotted down in pencil his thoughts 
and memoranda. He made his notes in the laboratory, in 
the theater, and in the streets. This distrust of his mem- 
