HERBARIUM. Vlj, 



to the system of Linnaeus or Jussieu. The student 

 who wishes to form such a collection will require some 

 instruction. 



When their flowers are fully expanded, the plants 

 should be gathered, placed between folds of paper, 

 and subjected to a moderate pressure until they are 

 thoroughly dry. When the specimens are numerous 

 or juicy, the papers should be frequently removed, 

 and others are to be substituted for those which have 

 imbibed the moisture of the plants, and the more faith- 

 fully this direction is followed, the more perfectly will 

 the specimens retain their original colour. Most plants 

 should be gathered when they are entirely dry, but 

 the Mosses may be collected at any season, thrown into 

 a vessel of water and then laid between the folds of mois- 

 tened writing paper, and subjected to pressure as in 

 other cases. The Mushrooms are preserved with the 

 greatest difficulty, and hence some have resorted to 

 models, and some to coloured engravings for the illus- 

 tration of that obscure class of vegetables. When the 

 specimens are thoroughly dry they are to be arranged 

 according to some method, and the papers to which 

 they are attached should contain the name, locality, 

 time of flowering, and whatever else is interesting res- 

 pecting the plants which are in this way preserved. 



An herbarium is frequently injured by insects as well 

 as by moisture ; and it is remarkable that plants of an 



