28 FIRST STEPS IN GENERAL KNOWLEDGE. 



matter which is highly inflammable, and is employed 

 under the name of Lycopodium, or Vegetable brim- 

 stone, in making fireworks, and in producing flashes 

 of light which feebly imitate lightning. It is also 

 used by the apothecary for rolling pills, which it pre- 

 serves from the effects of moisture. The whole plant 

 is emetic in its properties, as are some others of the 

 club-mosses. Woollen cloths boiled with lycopo- 

 diums acquire the property of becoming blue when 

 passed through a bath of Brazil wood. Club- 

 mosses are much more abundant in the moist, hot 

 climate of the tropics than in our temperate 

 region." 



" What plants come next to the mosses ?" asked 

 Eobert. 



" Near to mosses, but placed by some writers 

 below the split mosses, come those curious plants 

 called ' Horse-tails,'* which you see in ditches, and 

 often gather for the purpose of pulling apart the 

 numerous toothed divisions of the stem. These 

 plants are found in ditches and rivers in most parts 

 of the world. They are unimportant in a medical 

 point of view; but owing to their containing a 

 great quantity of silex, they are useful for polish- 

 * Equisetum, 



