264 FRAGMENTS OF SCIENCE. 
knowledge of facts from actual observation. Facts looked 
at directly are vital; when they pass into words half the 
sap is taken out of them. You wish, for example, to get 
a knowledge of magnetism; well, provide yourself with a 
good book on the subject, if you can, but do not be con- 
tent with what the book tells you; do not be satisfied with 
its descriptive woodcuts; see the operations of the force 
yourself. Half of our book writers describe experiments 
which they never made, and their descriptions often lack 
both force and truth; but no matter how clever or con- 
scientious they maybe, their written words cannot supply 
the place of actual observation. Every fact has numerous 
radiations, which are shorn off by the man who describes 
it. Go, then, to a philosophical instrument maker, and 
give a shilling or half a crown fora straight bar-magnet, or, 
if you can afford it, purchase a pair of them; or get a 
smith to cut a length of ten inches from a bar of steel an 
inch wide and half an inch thick; file its ends smoothly, 
harden it, and get somebody like myself to magnetize it. 
Procure some darning needles, and also a little unspun 
silk, which will give you a suspending fiber void of torsion. 
Make a little loop of paper, or of wire, and attach your 
fiber to it. Do it neatly. In the loop place a darning- 
needle, and bring the two ends or poles, as they are called, of 
your bar-magnet successively up to the ends of the needle. 
Both the poles, you find, attract both ends of the needle. 
Replace the needle by a bit of annealed iron wire; the 
same effects ensue. Suspend successively little rods of 
lead, copper* silver, brass, wood, glass, ivory, or whale- 
bone; the magnet produces no sensible effect upon any of 
the substances. You thence infer a special property in 
the case of steel and iron. Multiply your experiments, 
however, and you will find that some other substances, 
besides iron and steel, are acted upon by your magnet. A 
rod of the metal nickel, or of the metal cobalt, from which 
the blue color used by painters is derived, exhibits powers 
similar to those observed with the iron and steel. 
In studying the character of the force you may, however, 
confine yourself to iron and steel, which are always at hand. 
Make your experiments with the darning-needle over and 
over again; operate on both ends of the needle; try both 
ends of the magnet. Do not think the work dull; you are 
conversing with Nature, and must acquire over her lau- 
