392 FRAGMENTS OF SCIENCE. 
of surface are now covered by those beautiful forms. With 
another solution we obtain crystalline spears, feathered 
right and left by other spears. From distant nuclei in the 
middle of the field of view the spears shoot with magical 
rapidity in all directions. The film of water on a window 
pane on a frosty morning exhibits effects quite as wonder- 
ful as these. Latent in these formless solutions, latent in 
every drop of water, lies this marvelous structural power, 
which only requires the withdrawal of opposing forces to 
bring it into action. 
The clear liquid now held up before you is a solution of 
nitrate of silver a compound of silver and nitric acid. 
When an electric current is sent through this liquid the 
silver is severed from the acid, as the hydrogen was sepa- 
rated from the oxygen in a former experiment; and I would 
ask you to observe how the metal behaves when its mole- 
cules are thus successively set free. The image of the cell, 
and of the two wires which dip into the liquid of the cell, 
are now clearly shown upon the screen. Let us close the 
circuit, and send the current through the liquid. From 
one of the wires a beautiful silver tree commences im- 
mediately to sprout. Branches of the metal are thrown 
out, and umbrageous foliage loads the branches. You 
have here a growth, apparently as wonderful as that of 
any vegetable, perfected in a minute before your eyes. 
Substituting for the nitrate of silver acetate of lead, 
which is a compound of lead and acetic acid, the electric 
current severs the lead from the acid, and you see the 
metal slowly branching into exquisite metallic ferns, the 
fronds of which, as they become too heavy, break from 
their roots and fall to the bottom of the celh 
These experiments show that the common matter of 
our earth " brute matter," as Dr. Young, in his " Night 
Thoughts," is pleased to call it when its atoms and mole- 
cules are permitted to bring their forces into free play, 
arranges itself, under the operation of these forces, into 
forms which rival in beauty those of the vegetable world. 
And what is the vegetable world itself, but the result of 
the complex play of these molecular forces? Here, as 
elsewhere throughout nature, if matter moves it is force 
that moves it, and if a certain structure, vegetable or 
mineral, is produced, it is through the operation of the 
forces exerted between the atoms and molecules. 
