AmApdir'i9ib3arm' }     Change  from  Old  to  New  Botany.  155 
The  pharmacopoeial  tincture  contains  "  about  "  6.86  grams  of  free 
iodine  and  5  grams  of  potassium  iodide  in  100  c.c.  The  range  of 
variation  (1.97  to  9.26  grams  per  100  c.c.)  is  certainly  remarkable. 
What  real  valid  excuse  can  be  offered  for  either  of  the  above  ex- 
tremes? Furthermore,  is  there  any  substantial  reason  for  some  of 
the  other  variations?  The  permissible  variation  from  the  standard 
must  be  met  sooner  or  later.  Shall  it  be  stringent  or  reasonable? 
If  reasonable  shall  the  variation  be  5  per  cent,  or  10  per  cent,  or  20 
per  cent.?  Considering  that  the  adjective  "about"  qualifies  the 
amount  of  free  iodine  that  should  be  present  in  the  tincture,  about 
60  per  cent,  exceed  a  5  per  cent,  variation,  40  per  cent,  a  10  per 
cent,  variation  and  18  per  cent,  a  20  per  cent,  variation.  I  do  not 
believe  many  manufacturers  will  contend  for  or  advise  a  20  per  cent, 
variation  in  that  it  would  not  only  savor  of  carelessness  but  actually 
encourage  it.  Is  then  a  10  per  cent,  variation  either  way  from  the 
standard,  reasonable,  fair  and  just  to  the  manufacturer,  the  con- 
sumer, the  physician,  etc.,  or  is  it  desirable  to  be  more  stringent  ? 
Suggestions  are  invited  either  in  the  columns  of  this  journal  or 
otherwise.  The  free  iodine  is  the  essential  factor  of  this  tincture 
but  the  potassium  iodide  and  percentage  of  alcohol  must  also  be  con- 
sidered. The  conditions  noted  above  relative  to  the  variability  of  the 
free  iodine  also  holds  for  potassium  iodide.  The  variation  ranges 
from  no  potassium  iodide  to  6.82  grams  per  100  c.c.  Discussion  in 
this  connection  is  also  invited. 
THE  CHANGE  FROM  THE  OLD  TO  THE  NEW  BOTANY 
IN  THE  UNITED  STATES.1 
By  W.  G.  Farlow. 
It  is  generally  known  that  in  the  seventies  there  was  a  sudden 
development  of  the  study  of  botany  in  this  country.  Just  how 
and  why  this  sudden  development  took  place  at  that  particular  date 
is,  I  suspect,  not  clearly  recognized,  at  least  by  our  younger  men. 
From  histories  and  reports  of  progress  they  can  learn  the  main 
facts,  but  those  who,  as  students  or  instructors,  have  lived  through 
the  transitional  period  when  the  old  botany  was  changed  into'  the 
1  Address  of  retiring  president  of  the  Botanical  Society  of  America, 
given  at  the  Botanists'  Dinner,  Cleveland,  January  1,  1913. 
