342 
RED  WINES  ADULTERATED  WITH  ALUM. 
546).  These  statements  induced  Dr.  A.  Geuther  (Annalen  d. 
Chem.  and  Pharm.  1855,  Dec.  382)  to  examine  it,  and  he  found 
that  the  deutoxide  is  obtained  pure  whether  the  carbonate  of  soda 
used  be  pure  or  contain  chloride  of  sodium  ;  in  the  latter  case  the 
acetate  of  lead  must  gradually,  and  under  good  stirring,  be  poured 
into  the  carbonate  of  soda.  In  both  cases  a  deutoxide  was  ob- 
tained wholly  soluble  in  nitric  acid  under  the  addition  of  a  little 
alcohol,  and  this  solution  did  not  show  a  trace  of  chlorine  to  be 
present  when  treated  with  nitrate  of  silver.  Also,  Crum's  test 
was  obtained  by  heating  some  deutoxide  with  nitric  acid,  and 
adding  a  few  drops  of  some  solution  of  protoxide  of  manganese 
previously  diluted  until  sulphuret  of  ammonium  did  not  render 
it  turbid.  Maisch. 
ON  THE  CHARACTERS  OF  RED  WINES  ADULTERATED  WITH 
ALUM,  AND  THEIR  APPLICATION  TO  THE  DETECTION  OF 
SMALL  QUANTITIES  OF  THAT  SALT  INTRODUCED  INTO  WINE. 
By  J.  L.  Lassaigns. 
The  author  has  found  that  the  aluminous  salts,  when  dissolved 
in  red  wines,  are  partially  decomposed  with  more  or  less  rapidity, 
according  to  the  temperature  at  which  the  operation  is  carried 
on.  The  result  of  this  reaction  is  the  precipitation  of  a  colored 
compound,  formed  by  the  union  of  the  alumina  with  a  portion 
of  the  coloring  matter  of  the  wine ;  and  this  compound,  which 
varies  slightly  in  color  according  to  the  kind  of  wine,  is  a  true 
lake,  such  as  is  produced  by  alumina  with  most  of  the  organic 
coloring  principles. 
When  a  red  wine  is  boiled  for  a  few  minutes  with  a  very  small 
addition  of  alum,  it  gradually  becomes  turbid,  and  furnishes  a 
flocculent  precipitate,  which  collects  at  the  bottom  of  the  vessel 
when  the  wine  is  allowed  to  cool  and  stand ;  it  forms  a  com- 
pletely insoluble  lake.  This  deposit,  which  may  easily  be  sepa- 
rated by  decantation  and  filtration,  presents  reactions  character- 
istic of  the  color  derived  from  the  wine  itself;  when  calcined  in 
contact  with  the  air  in  a  platinum  crucible,  it  leaves  a  tolerably 
abundant,  white,  pulverulent  residue,  presenting  all  the  characters 
of  anhydrous  alumina. 
Pure  red  wines,  without  any  addition  of  aluminous  salt,  are 
