CRYSTALLIZATIONS. 103 



slide by the application of a very moderate heat. The resulting configurations 

 are of exceeding beauty, and no verbal description, or delineation of the artist, 

 can convey to the mind a full conception of the richness and elegance of the 

 forms that are presented the eye by the magic power of the microscope. Not 

 only is the beholder charmed with the wonderful delicacy and exquisite grace 

 of the figures ; but such is the swiftness with which the fluid crystallizes, that he 

 sees them in the very process of formation, darting forth their glittering filaments 

 in all directions with a velocity truly astonishing. A quick formation belongs 

 to nearly all the crystallizations herein described ; but the very rapid change of the 

 muriate of barytes from the liquid to the fluid state peculiarly impresses this 

 circumstance upon the mind. One combination common to this salt is found near 

 the edge of the crystallized field. It appears like a collection of shrubs, shorn 

 of their leaves, growing up from the midst of a tuft of rank herbage. The main 

 crystals take no particular direction in reference to each other, and the lateral 

 branches appear likewise to be guided in their course by no especial law. From 

 crystals like these numerous branches proceed, dividing and sub-dividing until an 

 infinity of boughs and sprays are seen, rising from a single stem, and groups and 

 groves of crystal trees spread their fairy foliage over the whole held of view. 



One part of this last assemblage of crystals is singularly connected with the rest; 

 for on the same side,, from a single point in the principal crystal, two shoots 

 emanate obliquely from it and at right angles to each other; but the lateral spurs 

 from these observe the same laws, in regard to direction, as those in other parts 

 of this combined figure. The size of the crystalline stems is exceedingly small, 

 the breadth in ordinary specimens being only one-seventeen hundred and sixtieth 

 part of an inch. 



The crystallizations of the muriate of barytes, like many others, exhibit an ex- 

 tremely beautiful appearance when viewed, not by the diffuse light of day, 

 but by a single light, as a lamp. Each crystal then acts as a prism in decompos- 

 ing the rays, and the entire field of view becomes illuminated with the splendor 

 of the sevenfold tints of the rainbow. 



In a third variety the main crystals are short and thick, their ramifications occu- 

 pying only a little space. The secondary crystals are parallel to each other and 

 perpendicular to the parent stem ; and from these a third system proceeds, gov- 

 erned by similar laws. 



Another beautiful configuration is sometimes formed in which the crystal- 

 line stems radiate from a common centre, and diverging more and more as 

 they recede from this point, push forth on either side buds and shoots of spark- 

 ling crystals, covering the entire circle throughout which they extend with clus- 

 tering gems. 



BICHROMATE OF POTASS A. This salt produces very elegant combinations, 

 the original form of the crystals being that of a four-sided prism. The solution 

 is of a transparent cherry color, and the minute crystals seen by the microscope 

 gleam with a rich amber light. Like those o^ the muriate of ammonia they form 



