304 USE OF A2tf 



as it appears, withheld from his auditors, lest 

 he should lead them into error. This will 

 explain a note in Professor Giseke's preface, 

 p. 19, which however was printed before his 

 request came to my knowledge ; for two very 

 intelligent friends, through whom it was meant 

 to be conveyed, judged it unreasonable to he 

 made, as well as improper to be complied 

 with, and therefore suppressed the message. 



I have only to add a few practical remarks 

 on the preparation and use of an Herbarium 

 or Hortus Siccus. The advantages of pre- 

 serving specimens of plants, as far as it can 

 be done, for examination at all times and 

 seasons, is abundantly obvious. Notwith- 

 standing the multitude of books filled with 

 descriptions and figures of plants, and how- 

 ever ample or perfect such may be, they can 

 teach no more than their authors observed j 

 but when we have the works of Nature before 

 us, we can investigate them for ourselves, 

 pursuing any train cf inquiry to its utmost 

 extent, nor are we liable to be misled by the 



