566  Gleanings  from  the  German  Journals.  { Amj/0Ov.T/imarm' 
observed.  The  solution  kept  in  black  bottles  lost  in  eighteen 
months  only  0-94  per  cent.  The  solution  (3  :  1,000)  was  found  to 
possess  still  greater  stability ;  kept  in  black  bottles  or  exposed  in 
colorless  bottles  to  diffused  daylight  no  change  in  the  strength  could 
be  detected  after  eighteen  months. 
Sodium  thiosulphate  solution. — The  normal  solution  at  the  end 
of  six  months  was  found  unchanged  when  kept  in  black  bottles  or 
exposed  to  diffused  daylight ;  it  seems,  however,  that  the  former  is 
the  more  permanent  method  of  keeping,  since  in  the  solution  in 
colorless  glass  a  mould  growth  developed  at  the  end  of  four 
months. 
Oxalic  acid  solution. — The  normal  solution  protected  from  light 
and  dust  was  not  altered  in  the  course  of  five  months ;  at  the  end 
of  a  year  a  loss  of  2-85  per  cent,  was  noticed.— Dr.  Bruno  Griitzner, 
Archiv  der  Pharm.,  1892,  321. 
Assay  of  crude  carbolic  acid. — Into  a  large  beaker  glass  are 
weighed  ioo-o  each  of  the  carbolic  acid  and  of  milk  of  lime  (made 
by  slaking  one  part  lime  with  five  parts  water),  the  vessel  placed  in 
a  steam-bath  and  heated  for  one  hour  with  frequent  stirring ;  an 
equal  volume  of  water  is  then  added  and  the  mixture  thoroughly 
stirred.  The  tarry  and  resinous  constituents  by  this  treatment  form 
insoluble  calcium  combinations,  while  the  phenol  and  cresol  enter 
solution  and  the  volatile  substances  are  dissipated.  After  cooling 
the  mixture  is  filtered,  the  residue  washed  with  water  and  the  filtrate 
decomposed  by  the  cautious  addition  of  hydrochloric  acid ;  to 
easily  separate  the  phenol  and  cresol  the  aqueous  solution  is  satu- 
rated with  salt,  this  causing  the  phenols  to  float  upon  the  brine ; 
after  removing  the  phenols  they  are  weighed  without  further  puri- 
fication. The  commercial  designation  of  crude  carbolic  acid  is 
based  upon  the  solubility  in  soda  solution,  an  acid  being  called 
IOO  per  cent,  if  it  dissolve  clear  in  the  soda  solution.  Treated  by 
the  above  process,  commercial  crude  carbolic  acid  of  25-30  per 
cent,  assayed  2-3  per  cent.;  40-60  per  cent,  assayed  3-5  per  cent.  > 
80  per  cent,  assayed  50  per  cent.,  and  specimens  marked  90-100 
per  cent,  assayed  80  per  cent,  of  phenol. — F.  Seiler.  Schwz. 
Wochenschr.f.  Chem.  u.  Pharm.,  1892,  365. 
Mercuric  oxide. — To  determine  the  influence  of  temperature  in  the 
preparation  of  precipitated  mercuric  oxide  C.  Guldensteeden  Egel- 
