CRYSTALLIZATION OF GOLD^ SILVER, ETC. 435 



assume the appearance of fern-leaves ; while the growth from a still 

 stronger liquid reminds us rather of a furze-bush. If the nitrate of sil- 

 ver amount to fifteen per cent, or thereabouts, there occurs a steady 

 •advance of brilliantly white moss ; and, if the solution be saturated, or 

 nearly so — say forty per cent. — this moss is very sturdy, often ending 

 in solid crystalline knobs, or stretching out into the liquid as an arbo- 

 rescent fringe. 



In all these cases, however, when the solution in front of the grow- 

 ing crystals has been somewhat exhausted, certain prominent or well- 

 circumstanced crystals seem to monopolize the power, and to push for- 

 ward through the remaining portions of the liquid. This raises beauti- 

 ful branches which assume a variety of graceful forms, which it is hope- 

 less to attempt to portray by diagrams, but the subjoined figures give 

 some of the more characteristic outlines greatly magnified. The weak 

 solutions produce feathery crystals, as somev/hat in Fig. 1, consisting of 



Fig. 1. 



Fig. 2. 



a straight central stem from which grow on either side crystalline rays 

 that terminate in a sharp point, and frequently become themselves the 

 center stem of a similar crystalline structure. 



In the outlying growth of a moderately strong solution the apparent 

 regularity of the crystalline form is lost ; the main stem is built of a 

 confused mass of hexagonal plates, while the side branches are an ag- 

 glomeration of minute pointed crystals turning in every direction, and 

 producing such jagged outlines as in Fig 2. 



Fig. 3. 



Fig. 4. 



In still stronger solutions the branches lose every appearance of 

 straightness, and they are built of hexagonal plates so studded with 



