AMERICAN INSTITUTE. 445 



frequently contains more than one hundred long eels. The vinegar eel is 

 larger, and more tapering, which enables it to move with great celerity in 

 its native element. It is oviparous and viviparous. 



One of the most beautiful discoveries of the microscope is that which 

 reveals to us the strange fact that bodies when they pass slowly to the solid 

 state from the liquid, assume singular forms of great beauty and elegance, 

 termed crystallizations, each having the form of the primitive crystal; 

 many of which frequently combine and give rise to a magnificent collection 

 of perfectly symmetrical figures. A very large portion of the mineral crust 

 of our earth is in a crystallized condition. Take the granite for example, 

 which the microscope informs us is composed of crystals of mica, quartz, 

 and feldspar. All the clay slate hills are mainly constituted of regular 

 forms. Fluid bodies become crystals. Salt may be converted into brine, 

 so that no separate particle can be observed, and when evaporated, will 

 immediately form crystals. Sulphur may be melted, and allowed to cool 

 gradually, when it forms beautiful crystals, at first so minute that they 

 almost elude the most powerful microscope, but as they unite the most 

 magnificent configurations are seen branching out in all directions, with 

 perfect symmetry, representing foliage crowded together in rich clusters. 

 Nitrate of potash may be dissolved, spread on a piece of glass, and sub- 

 jected to heat, when six-sided prisms, perfectly transparent, will spring up 

 under the microscope, throw out lateral spurs, and finally spread over the 

 surface of the glass in beautiful lines of crystallized net work. In the East 

 Indies, nitrate of potash forms in the same manner upon the earth's sur- 

 face, and are swept into piles, and leached, as we do ashes — the liquid is 

 then evaporated, and the result is the crystalized nitre of commerce. A 

 drop of benzole acid exhibits the most splendid crystallizations under a 

 powerful microscope ; transparent sharp crystals, perfectly colorless are first 

 seen, and they afterwards rapidly run into vines and lovely foliage, which 

 spreads its glittering branches on every side, gleaming like sprays of silver. 

 If you would be perfectly delighted, dissolve the acid in alcohol, and spread 

 the liquid upon a pane of glass, then bring your microscope immediately to 

 bear, as the evaporation is rapid ; in an instant, the chaotic surface becomes 

 studded profusely with every imaginable combination of exquisitely beau- 

 tiful crystalline figures, the crystals composing which are only one seven 

 hundredth part of an inch in size. 



Copperas crystallizes in rhomboidal transparent prisms of a sea gi'een 

 color, and when observed under the microscope exhibit very interesting 

 combinations. Crystals at first display themselves in a vertical position, 

 and then branches push from them on every side, with great order and pre- 

 cision, and look like bristling arrows, which at length apparently form a 

 massive structure, still revealing the primitive crystal, through the mingled 

 shadows and lights that fall upon the crystalized surface, and these may be 

 varied by adjusting the mirror, when the illumination will shine brightly 

 upon some magnificent cluster, and again falls subdued upon the minute 



