568         Conservation  and  Cultivation  of  Plants.      { ADecimber^ iqoT" 
economically  to  produce  uniform  products,  and  to  devote  more 
attention  to  the  curing  of  the  drug,  which  is  usually  shown  in  the 
appreciation  of  the  article  by  the  physician  as  well  as  by  the  better 
price  which  it  commands. 
Mr.  Wm.  Krebs  1  has  given  some  interesting  data  on  the  yield  of 
the  drug  from  the  fresh  material,  and  I  have  summarized  some  of 
his  data  without,  however,  confirming  them  myself. 
The  yield  of  dried  drug  is  usually  about  20  per  cent,  of  the  fresh 
material  in  such  roots  as  Taraxacum,  Phytolacca  and  Lappa ;  rhi- 
zomes, as  Sanguinaria,  Hydrastis,  Asarum  and  Calamus ;  and  herbs, 
as  Nepeta  Cataria,  Leonurus  Cardica,  Hedeoma,  Mentha  piperita, 
Scutellaria,  Tanacetum  and  Gaultheria.  In  other  instances  the 
yield  of  crude  drug  is  only  about  10  percent,  of  the  original  weight, 
as  of  Eupatorium,  Stramonii  Folia  and  Achillea  millefolium.  In 
still  other  cases  the  loss  is  much  less,  as  in  Aspidium,  Cimicifuga, 
Caulophyllum,  Castanea,  Hamamelis  and  Rumex,  where  the  yield 
is  about  30  per  cent.  In  the  case  of  hops  the  yield  of  drug  is  over 
65  per  cent. 
CONCLUSION. 
The  American  people  are  awakening  to  the  necessity  of  the  pre- 
servation of  our  native  forests  and  of  our  wild  flowers.  We  are 
beginning  to  realize  that  the  care  ot  our  native  plants  is  a  trust, 
and  are  becoming  aware  that  even  our  own  safety  and  sustenance  is 
dependent  upon  the  intelligence  which  we  exercise  in  the  care  of 
them.  We  are  aroused  to  the  fact  that  the  products  of  nature  are 
for  us  to  legitimately  use  and  conserve,  and  that  we  owe  it  to  gen- 
erations unborn  to  study  them  in  their  various  relations  to  each 
other  and  their  subservience  to  man's  needs. 
We  are  conserving  plants  and  improving  them  by  cultivation, 
and  they  serve  us  either  for  ornament,  food  or  medicine.  Probably 
the  largest  number  of  plants  that  are  cultivated  are  those  which 
are  used  for  ornamental  purposes.  Many  of  these,  as  we  have 
stated,  also  are  valuable  remedial  agents  and  we  see  thus  that  the 
movements  for  the  preservation  of  our  forests  and  wild  plants  are  of 
interest  to  the  medical  and  pharmaceutical  profession. 
While  the  conservation  and  cultivation  of  medicinal  plants  in  this 
1  Merck's  Market  Report,  January  15,  1895,  p.  22. 
