MISCELLANEOUS. 323 



branches, but flat so. as to lie upon the glass, lay 

 it in the liquid, and let it remain for an hour or 

 two. A beautiful vegetation will be perceived all 

 round the wire, which will nearly be covered by 

 it. This may be preserved by washing it very 

 carefully with water, and putting another glass 

 over it. 



To produce a Tree of Lead. 



Dissolve an ounce of sugar of lead in a quart of 

 clear water, and put it into a glass decanter or 

 globe. Then suspend in the solution, near the 

 top, a small piece of zinc of an irregular shape. 

 Let it stand undisturbed for a day, and it will 

 begin to shoot out into leaves, and apparently to 

 vegetate. If left undisturbed for a few days, it 

 will become extremely beautiful ; but it must be 

 moved with great caution. 



It may appear to those unacquainted with che- 

 mistry, that the piece of zinc actually puts out 

 leaves ; but this is a mistake, for if the zinc be ex- 

 amined, it will be found nearly unaltered. This 

 phenomenon is owing to the zinc having a greater 

 attraction for oxygen than the lead has ; conse- 

 quently, it takes it from the oxyde of lead, which 

 re-appears in its metallic state. 



Arbor Martis, or Tree of Mars. 



Dissolve iron filings in aqua fortis moderately 

 concentrated, till the acid is saturated ; then add 

 to it gradually a solution of fixed alcali, formerly 

 called oil of tartar per deliquium. A strong ef- 

 fervescence will ensue, and the iron, instead of 

 falling to the bottom of the vessel, will afterwards 



