LETTER L. 



AN ARTIFICIAL METHOD OF DISCOVERING WITH CER- 

 TAINTY THE NATURAL ORDER TO WHICH A GIVEN 

 PLANT BELONGS. 



It is to be supposed that you are by this time well 

 grounded in the distinctions of the commoner Na- 

 tural Orders of plants ; and my last letter will 

 have furnished you with the means of arranging your 

 knowledge in a methodical way. I, therefore, might 

 with this have left you to your own resources in future, 

 or have referred you to the higher systematical works 

 of Botanists, for the means of carrying your inquiries 

 further. But I am so anxious to remove every 

 impediment from your path, that I have prepared for 

 you a set of tables, by means of which you may with 

 certainty discover to what Natural Order any given 

 plant belongs, without being obliged to examine it so 

 minutely as is in some instances necessary in a natural 

 arrangement. 



You will, doubtless, have remarked, that some of the 

 distinctions between the groups, as disposed in my 

 last letter, are minute, and difficult to discover j espe- 

 cially those which are taken from the structure of the 

 seed. You will also find, in practice, that there are 

 many exceptions to the characters of the subclasses 

 and groups ; for instance. Virgin s Bowei' (Clematis), 

 Spurge (Euphorbia), Mares-tail (Hippuris), and La- 



