54 THE ART OF PROJECTING. 



THE TIN TREE. 



Take a rather dilute solution of chloride of tin, made 

 by dissolving the crystalline proto-chloride in water, in 

 the proportion of one part of the former to four or five of 

 the latter. This solution will precipitate its tin upon a 

 piece of zinc in the same manner as the lead solution 

 will, but the form of the crystals is very different. Use 

 the same tank, and a magnifying power of 400 or 500 

 diameters, if good sunlight can be had. The growth 

 will be quite rapid, and crystals six or eight feet long 

 ought to appear. This needs no battery. Solutions 

 of any degree of concentration can be used, but the 

 growth is so rapid in very strong solutions, that the 

 masses interfere with each other, and are dense and 

 imperfect in form. Solutions can be used that are as 

 dilute as twenty or more parts of water to one of the 

 crystalline chloride. 



THE SILVER TREE. 



A solution of nitrate of silver is put into the tank, 



and a piece of fine copper wire put into it, the wire 



being nicely focused upon the screen. Pure silver will 



be immediately deposited in arborescent forms upon 



the wire, but the forms will vary with the strength of 



the solution. The more diluted it is, the finer will be 



the threads of silver. 



It is better to place 



the metal w that is to 



have the deposit upon 



it, whether of copper or 



zinc, so that it is just 



below the surface (s) 



of the solution, for the 



Fig. 34:. reason that when it is 



