PREFACE. 
A VARIETY of methods haye been adopted by authors 
for the arrangement of plants, in order that the knowledge 
mankind possesses of them may be more readily communi- 
cated to students in botany. The ancient authors consi- 
dered only the uses of plants, and arranged them accord- 
ingly into timber or fruit trees, corn, pulse, culinary and 
medicinal plants, those used for dyeing, for garlands, for 
spinning or other mechanical purposes, and ie like; while, 
as a kind of supplementary knowledge, those whose pro- 
perties rendered them deleterious to man himself or to the 
animals bred or domesticated by him were considered under 
the title of poisons; and those which impeded the growth 
of the plants cultivated by him were arranged under the 
general name of weeds; while the great mass of vegetables, 
to which neither usefulness nor harm could be attributed, 
were slighted, and indeed entirely neglected, unless any of 
them presented a phenomenon that struck forcibly on the 
attention, as the apparently sensitive property of the mimosa, 
or the water-dropping faculty of the nepenthes distillatoria. 
Succeeding authors have been more philosophically inclined, 
and have wished to bestow an equal degree of attention 
upon all the productions of the Almighty Creator, to the 
end that those now esteemed as useless may be pointed out 
for future investigation. The botanists of this school have 
given us general or local catalogues of plants, arranged 
either in the alphabetic order of their names, or according 
to the periodical time of their flowering, or partly from the 
whole period of their growth in the open air and partly 
from the contrivances they require to produce an artificial 
