320 
GLEANINGS  FROM  GERMAN  JOURNALS. 
Tea  yields,  according  to  Hlasiwetz  and  G.  Molin,  besides  tan- 
nin, also  gallic  acid,  oxalic  acid  and  quercetin ;  the  latter  prob- 
ably derived  from  quercitrin ;  boheie  acid  appears  not  to  be  a 
distinct  compound.    (Ibid.,  3.) 
Permanganate  of  potassa.  J.  C.  Sticht  employs  the  materials 
nearly  in  the  proportion  recommended  by  Woehler.  500  parts 
freshly  prepared  solution  of  potassa,  of  45°  Beaume,  are  evapo- 
rated with  105  p.  pure  chlorate  of  potassa ;  182  parts  of  black 
oxide  of  manganese  are  gradually  added,  and  the  mass  rendered 
anhydrous,  .when  it  is  allowed  to  cool,  with  continued  agitation, 
to  obtain  it  in  a  coarse  powder.  This  is  heated  in  small  iron 
kettles,  of  about  3  gallons  capacity,  to  dull  redness  and  semifu- 
sion.  When  cool  the  mass  is  removed,  broken  into  small  pieces, 
and  heated  with  water.  The  red  solution  is  allowed  to  rest  for 
12  hours,  then  drawn  into  copper  kettles  and  evaporated  below 
the  boiling  point ;  when  disposed  to  crystallize  on  cooling,  the 
fire  is  withdrawn,  and  after  some  time  the  clear  liquid  drawn 
into  crystallizing  vessels  of  copper  or  stone.  The  crystals  are 
collected  in  a  glass  filter,  washed  with  some  cold  water  and  dried. 
The  residue  in  the  iron  kettle  is  exhausted  with  water  and  crys- 
tallized in  the  same  manner.  The  weakest  solution  may  be  used 
for  the  next  operation.  When  the  liquor  assumes  a  green  color 
it  contains  manganate  of  potassa  and  chloride  of  potassium,  and 
may  be  used  for  the  generation  jof  chlorine  by  the  addition  of 
sulphuric  acid,  or  converted  into  permanganate  by  passing  chlo- 
rine through  it,  when  25  per  cent,  more  of  that  salt  may  be  ob- 
tained. 182  lbs.  black  oxide  of  manganese  yielded  98  to  100 
lbs.  permanganate  of  potassa  in  long  crystals.  (Wittst.  Yier- 
teljahresschrift,  1866). 
Fuchsin  as  a  test  for  alcohol  in  volatile  oils  was  recommended 
by  Puscheri  H.  Zeise  finds  that  fuchsin  is  dissolved  by  the 
freshly  distilled  oils  of  bitter  almonds,  cloves,  cinnamon,  cinna- 
mon-buds, coriander,  allspice,  mustard,  and  white  sandal  wood : 
old  oil  of  peppermint  and  of  crisped  mint  likewise  dissolve  it. 
It  was  however  found  to  be  insoluble  in  the  oils  of  cascarilla,  co- 
paiba, cubebs,  sassafras,  mace,  pepper  and  ginger.  (N.  Jahrb.  f. 
Ph.,  1867,  Febr.,  81). 
