250  Constituents  of  Ericaceous  Plants. 
The  addition  of  water  is  not  indispensable,  if  the  iodide  is  intro- 
duced carefully  little  by  little  and  the  liquid  well  agitated.  If  these 
precautions  are  not  observed,  the  iodide  dissolving  rapidly,  will  locally 
precipitate  some  bromide,  and  render  the  result  doubtful.  If  10  drops 
of  water  are  previously  added  to  the  10  c.c.  of  the  saturated  solution 
this  inconvenience  is  avoided. 
The  water  added  will  scarcely  dissolve  any  bromide  of  potassium. 
In  making  the  experiment  before  the  Pharmaceutical  Society  of  Ant- 
werp, a  small  fragment  of  bromide  was  mixed  with  1  grm.  of  iodide  of 
potassium,  and  remained  unaltered  for  at  least  twenty  minutes  after 
the  gradual  addition  and  solution  of  the  iodide. 
The  author  recommends  this  perhaps  more  empirical  than  scientific 
process,  not  with  the  view  to  supersede  the  more  exact  though  more 
tedious  ones,  but  rather  as  a  quick  and  practical  method  to  detect  the 
falsification  of  iodide  with  bromide  of  potassium,  as  well  as  its  substi- 
tution by  the  latter  salt. 
ON  SOME  CONSTITUENTS  OF  ERICACEOUS  PLANTS. 
By  Jefferson  Oxlet. 
From  the  Author's  Inaugural  Essay. 
Of  this  order  Uva  ursi  and  Chimaphila  umbellata  have,  upon  ex- 
amination, been  found  to  contain  arbutin,  urson  and  ericolin.  Think- 
ing it  of  some  interest  to  know  if  these  principles  are  alike  common 
to  other  plants  of  the  same  order,  Graultheria  procumbens  and  Epi- 
gcea  repens  were  submitted  to  examination. 
From  two  pounds  of  Graultheria,  as  usually  found  in  market,  after 
removing  the  larger  stems,  the  remaining  leaves  and  smaller  stems 
weighed  one  pound  and  six  ounces,  showing  a  loss  of  31  per  cent. 
Garbling  one  pound  and  a  half  of  Epigcea  repens  in  the  same  man- 
ner, one  pound  of  leaves  and  small  stems  remained,  indicating  a  loss 
of  33  per  cent. 
Reduced  to  a  convenient  powder  they  were  digested  with  water 
during  several  hours,  strained  and  expressed,  and  a  second  time  sub- 
mitted to  like  treatment.  Upon  drying  the  residue,  the  Gaultheria 
weighed  twelve  ounces,  a  loss  of  45  per  cent.  Epigaia  repens  weighed 
ten  and  a  half  ounces,  a  loss  of  about  34  per  cent. 
The  infusions  were  treated  with  neutral  acetate  of  lead,  the  fil- 
trates with  subacetate  of  lead,  and  filtered.  The  resulting  solutions 
were  almost  free  from  color,  being  a  light  yellow.    The  lead  was  re- 
Am.  Jock.  Phakm  . 
June  1,  1872. 
