. INTRODUCTION. 
A compromise between these aims must be effected deter 
Eo ’° nomic 
they L eve * , C ° me a 80ienoe > and its professors, if 
emL m6 I ° 0re au “ “ere rale-of-thumb 
staple prodocttrr 011 m ’ 18t ’ " aral<S ’ be de™*edtoth. 
zsr* r r 
and the physiological y tbe Bta <Iy of vegetable prodncts 
^that^ern^c^dryf^Lty 
»n”o i r:;r ii86nuy to ™ «• 2- 
go tao^l'th'T'^’ the 8tndent ot Economic Botany most 
products, this hnoTthTth^ a " ClaBSeB ° f Tegetable 
What he want* • h he general requires. 
n - . . ms 18 a succinct statement of the rproivn^ 
at which'its ^ 
facts aboot the more imseoT ^ * h esseDtlal detailed 
-tlines o, the more ““ ^ - ** 
dacts, sufficient to guide him from * , * nor P r °- 
them- It is from this point of yie^t^ W “ h 
** written. ttut tie Present work 
The Sources i 
Products , 
Products of value are 4 = 
°* different plants, and from a g^t n T™ “"“h" 
Partsof plants. Roots, stems . great number of different 
atamens, fr aits, seeds, 4 c., a „’j 1 ™^ b,,lbe > tnbw », flowers, 
P 0881 ole sources of valuable 
