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 cell. 



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. 



