15 
Gentlemen, are debarred, excepting a few days occasionally, 
from leaving home; but are you, on that account, to give 
up the study of Natural History? No; but, on the contrary, 
it should induce you to set the higher value on books, for in 
them you find that knowledge which circumstances prevent 
you from obtaining by personal observation, and an immense 
mass besides, which otherwise you could not possibly acquire. 
Dr. Arnot, in the Introduction to his admirable “ Ele- 
ments of Physics,” observes, that, “‘ in England, a man of 
small fortune may cast his looks around him, and say, with 
truth and exultation, ‘I am lodged in a house that affords 
me conveniences and comforts which even a _ king 
could not command some centuries ago. Ships are cross- 
ing the seas in every direction, to bring me what is useful 
to me from all parts of the earth. In China, men are ga- 
thering the tea-leaf for me ; in America, they are planting 
cotton for me ; in the West India islands, they are prepar- 
ing my sugar and my coffee ; in Italy, they are feeding silk- 
worms for me ; in Saxony, they are shearing the sheep to 
make me clothing; at home, powerful steam-engines are 
spinning and weaving for me, and making cutlery for me, 
and pumping the mines, that minerals useful to me may be 
procured. Although my patrimony was small, I have post- 
coaches running day and night, on all the roads, to carry 
my correspondence ; I have roads, and canals, and bridges, 
to bear the coal for my winter fire: nay, I have protecting 
fleets and armies around my happy country to secure my 
enjoyments andrepose. Then, I have editors and printers, 
who duly send me an account of what is going on through- 
out the world, among all these people who serve me. And, 
in a corner of my house, I have books! the miracle of all 
my possessions, more wonderful than the wishing-cap of 
