THE  PRESENCE  OF  IODINE  IN  VARIOUS  PLANTS. 
67 
in  the  locks  near  Edinburgh,  to  ascertain  whether  they  contained 
iodine.  The  plants  were  dried  carefully,  reduced  to  charcoal  with 
the  lowest  heat  compatible  with  the  complete  destruction  of  the  or- 
ganic matter,  the  residue  reduced  to  fine  powder,  lixiviated  by  di- 
gestion in  water,  and  the  clear  liquid  evaporated.  In  every  case 
Dr.  Price's  process  was  employed  for  detecting  the  iodine,  viz  : 
with  nitrite  of  potash  and  hydrochloric  acid. 
Mr.  Macadam  has  detected  iodine  in  the  following  plants  not 
previously  known  to  contain  it,  viz  : 
Myosotis  palustris,  Ranunculus  aquatilis, 
Mentha  sativa,  Potamegeton  densus, 
Menyanthes  trifoliata,  Chara  vulgaris, 
Equisetum  limosum, 
And  has  confirmed  its  presence  in  : 
Iris  pseudo-acorus,  Phragmites  communis, 
and  in  the  ashes  of  coal. 
As  having  some  connection  with  the  subject  treated  of,  the 
author  indicated  that  he  had  obtained  distinct  indications  of  the 
presence  of  bromine  in  the  crude  potashes.  It  is  unfortunate  that 
our  tests  for  bromine  are  so  much  inferior  in  delicacy  to  those  of 
iodine  that  it  is  necessary  to  operate  upon  very  large  quantities 
before  the  tests  are  distinct.  There  is  no  doubt  that  from  its  pres- 
ence in  trees  it  will  be  found  in  greater  abundance  in  the  more 
succulent  plants  ;  but  the  few  trials  yet  made  have  been  unsuc- 
cessful in  determining  its  presence  in  any  but  crude  Canadian  and 
American  potashes. 
[This  statement  of  Mr.  Macadam,  that  he  was  only  able  to  find  bromine 
in  American  and  Canadian  potashes,  may  probably  be  explained  by  the  fact 
that  the  American  potash  manufacturers  are  much  in  the  habit  of  adding 
common  salt  to  their  ashes  before  leaching  them,  as  well  as  to  the  potash 
kettle  during  the  final  fusion  of  the  crude  alkali,  ostensibly  for  the  pur- 
pose of  rendering  it  purer  and  more  fusible,  but  practically  because  it 
increases  its  weight.  The  result  of  its  use  is  that  a  considerable  portion 
of  potash  is  converted  into  chloride  of  potassium,  whilst  the  soda  base  of 
the  common  salt  becomes  carbonate  of  soda;  thus  materially  injuring  the 
article  in  commercial  value.  Now  it  is  well  known  that  many  if  not  all 
the  salt  springs  of  the  interior  of  New  York,  Pennsylvania  and  Virginia, 
contain  bromide  of  sodium,  often  in  such  quantity  as  to  be  largely  employed 
for  extracting  bromine.  Now,  may  not  the  common  salt  derived  from  this 
source,  and  which  is  used  by  the  makers  of  potash,  be  the  origin  of  the 
\ 
