METHOD  OF  PREPARING  PROTIODIDE  OF  MERCURY.  9 
sence  of  tannin.  To  it  acet.  of  lead  was  added  as  long  as  it  gave 
a  precipitate,  then  filtered  and  sulphydric  acid  passed  through 
it  to  precipitate  the  excess  of  lead  salt  used,  filtered  and  mixed 
with  half  its  volume  of  ether  and  agitated  for  some  time.  After 
standing  some  time,  to  allow  the  ether  to  separate,  it  was  poured 
off  and  left  to  spontaneous  evaporation.  A  light  yellow  substance 
insoluble  in  water,  soluble  in  alcohol  and  of  an  exceedingly  bit- 
ter taste,  was  the  result.  I  intend  to  treat  it  at  some  more  con- 
venient season,  after  the  method  of  Duval  for  obtaining  casca- 
rillin,  which  bark  (cascarilla)  it  much  resembles,  as  far  as  its 
proximate  constituents  are  concerned,  and  perhaps,  also,  its 
medicinal  properties.  We  here  find,  also,  a  close  similarity  in 
the  Malambo,  the  Copalchi  and  this  unknown  (to  me)  bark. 
Like  the  Malambo,  it  apparently  contains  no  tannin,  two  oils  of 
different  specific  gravity,  a  bitter  principle,  no  alkaloid.  The 
Copalchi  resembles  them,  &c.  And,  to  sum  up  the  whole,  the 
evidence  is  so  conclusive  to  me,  that  I  have  no  hesitancy  in  saying 
that  the  Malambo  bark  described  by  Ure,  the  Copalchi  by  Stark 
and  Pereira  as  Corky  Copalchi  and  the  bark  in  question  are 
identical. 
Cincinnati,  December ;  1856. 
REMARKS  ON  BOUTIGNY'S  METHOD  OF  PREPARING  PROT- 
IODIDE OF  MERCURY. 
By  John  Canavan. 
Prof.  Procter: — Dear  Sir, — In  the  last  number  of  your 
Journal,  there  are  some  remarks  on  M.  Boutigny's  process  for 
preparing  the  protiodide  of  mercury,  by  Mr.  Bullock,  which 
attracted  my  attention,  as  a  similar  result  has  taken  place  under 
my  own  notice,  which  I  think  I  can  explain,  at  least  satisfactorily 
to  myself. 
Having  always  prepared  the  above  salt  according  to  M.  Bou- 
tigny's formula,  and  with  success,  I  was  surprised,  a  few  days 
since,  by  a  quantity  shown  me,  prepared  by  an  assistant,  which 
contained  large  globules  of  metallic  mercury.  As  it  was  too  late 
to  examine  the  washings,  (not  having  seen  it  until  in  the  drying 
process,)  I  questioned  the  assistant  as  to  the  manner  in  which 
he  proceeded;  he  replied,  he  went  exactly  according  to  the  "  di- 
