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AMMONIO-OXIDE  OF  COPPER. 
ON  AMMONIO-OXIDE  OF  COPPER,  A  SOLVENT  FOR 
VEGETABLE  FIBRE. 
By  Dr.  Ed.  Schweizer. 
The  author  prepared  basic  hyposulphate  of  copper,  4CuG, 
S205,  by  carefully  precipitating  a  solution  of  hyposulphate  of 
copper  with  dilute  ammonia.  The  precipitate  was  filtered,  wash- 
ed, and  then  treated  with  strong  ammonia,  in  which  it  very 
readily  dissolved  up  to  a  dark  blue  liquid,  from  which,  on  cool- 
ing, crystals  of  cuprohyposulphate  of  ammonia,  2NH3CuO,  S205, 
were  deposited.  Hence  by  dissolving  the  basic  salt  in  ammonia, 
there  must  have  been  formed  some  ammonio-oxide  of  copper 
which  remained  in  solution. 
This  blue  liquid  has  the  very  remarkable  property  of  dissolv- 
ing vegetable  fibre  at  ordinary  temperature. 
When  clean  cotton  is  treated  with  this  blue  liquid,  it  soon  as- 
sumes a  gelatinous  consistence,  the  filaments  separate  and  dis- 
appear, and  after  some  kneading  with  a  glass  rod,  the  whole  is 
changed  into  a  mucous  liquid.  No  heat  is  given  out  in  this 
operation.  If  sufficient  liquid  has  not  been  employed,  a  portion 
of  the  fibre  remains  visible  ;  but  on  adding  an  excess  and  agita- 
ting, it  disappears,  and  an  almost  colorless  solution  is  obtained, 
which  after  dilution  with  water  may  be  filtered. 
On  supersaturating  the  solution  with  hydrochloric  acid,  a  volu- 
minous white  precipitate  is  formed,  which,  collected  on  a  filter, 
has  the  appearance  of  moist  hydrated  oxide  of  alumina.  This 
appears  to  be  nothing  more  than  cellulose,  which  is  disorganized, 
but  not  essentially  altered  in  its  chemical  nature. 
When  the  gelatinous  precipitate,  thoroughly  washed  from  salts, 
is  suspended  in  water,  iodide  of  potassium  added,  and  then  a 
little  chlorine-water,  the  liquid  becomes  brown,  a  proof  that 
neither  starch  nor  amylaceous  substances  are  present.  Dried  on 
the  water-bath,  the  precipitate  diminishes  in  bulk,  and  leaves  a 
horn-like,  transparent,  brittle  mass,  resembling  dried  starch- 
paste,  but  having  no  taste.  Heated  in  the  air,  it  burns  away 
without  residue. 
Paper  and  linen  are  also  dissolved,  though  somewhat  more 
slowly  than  cotton ;  and  the  solvent  power  extends  to  some  ani- 
