158 
REMARKS  ON  UNTINNED  COPPER  VESSELS. 
in  the  trees,  produced  by  the  Indians  by  the  application  of  fire 
to  the  foot  of  the  tree.    The  Indians  eat  this  sugar. 
The  author  extracted  a  crystallizable  matter  by  means  of  water 
from  the  crude  substance.  This  he  calls  finite.  Its  composition 
is  C12H12010.  It  tastes  nearly  as  sweet  as  sugar-candy.  It  is 
readily  soluble  in  water,  and  nearly  insoluble  in  absolute  alcohol, 
but  dissolves  a  little  in  boiling  ordinary  alcohol.  Its  specific 
gravity^  1«52.  Its  right  rotation  is  (a)j= -j-58°«6  (with  refer- 
ence to  the  transition-color.)  Finite  does  not  reduce  the  oxide 
of  copper  in  solution  of  oxide  of  copper  and  potash,  even  after 
treatment  with  sulphuric  acid.  When  precipitated  with  ammonia- 
cal  solution  of  acetate  of  lead,  it  furnishes  a  compound  of  the 
formula  C12H12O10-f4PbO.  It  is  consequently  isomeric  with 
quercite,  and  is  distinguished  from  that  sugar  by  its  crystalline 
form,  its  stronger  sweet  taste,  and  its  great  solubility.  It  is  not 
capable  of  fermentation. 
3.  Sugar  fr 077i  Cider. — The  author  has  extracted  from  certain 
ciders  a  crystallizable  sugar,  which  is  isomeric  with  mannite. 
With  regard  to  its  crystallization  and  solubility,  it  is  also  identi- 
cal with  mannite. — Ibid,  from  Comptes  Rendus,  September  1855. 
REMARKS  ON  UNTINNED  COPPER  VESSELS. 
By  M.  Vasey,  Pharmacien  of  Luneville. 
M.  Yasey  recently  made  an  extract  of  the  leaves  of  elder 
with  the  expressed,  non-purified  juice  of  the  leaves  according  to 
the  process  of  Storck  of  Vienna.  He  operated  in  a  red  copper 
vessel  which  was  untinned,  and  perfectly  free  from  rust.  The 
liquid  on  commencing  to  boil  was  agitated  with  a  clean  iron 
spatula  to  avert  the  ebullition.  After  a  few  moments  on  with- 
drawing the  spatula,  he  was  surprised  to  see  it  covered  with  a 
layer  of  copper.  At  first  he  could  not  account  for  this  result. 
He  cleaned  the  spatula  and  again  agitated  the  liquid  with  it, 
but  this  time  instead  of  copper  it  was  covered  with  a  black  layer, 
resulting  probably,  from  the  reaction  of  the  tannin  with  the 
iron  ;  several  repetitions  of  this  trial  with  a  clean  spatula  showed 
no  trace  of  copper. 
M.  Vasey  explains  this  phenomenon  by  assuming  that  a  part 
of  the  carbonic  acid  existing  in  the  juice  acted  on  the  copper  to 
