164  Gleanings  from  the  European  Journals.  {AMAp,Ti)i872RM' 
with  the  addition  of  some  mucilage  to  prevent  the  rapid  escape  of  the 
gas  when  the  cork  is  removed. — Ibid.,  210-214. 
Powdered  French  Chalk  is  recommended  by  Mylius  for  rolling  pills 
of  nitrate  of  silver  made  with  white  bole;  the  smooth  surface  imparted 
to  the  pills  may  probably  recommend  its  use  in  other  cases. — Ibid., 
215. 
Finely  Divided  Phosphorus. — Mylius  suggests  to  fuse  the  phos- 
phorus under  water,  to  which  some  white  clay  or  asbestos  has  been 
added,  and  agitate  until  cold.  On  shaking,  a  uniform  milk-like  mix- 
ture is  obtained,  in  which  the  finely  divided  phosphorus  is  kept  sus- 
pended sufficiently  long  to  be  weighed  out  correctly. — Ibid.  216. 
Pommade  tannique  pour  la  regeneration  des  cheveux  blancs,  pre- 
pared by  Filliol  &  Andoque,  Paris,  contains,  according  to  A.  Geheeb, 
no  tannin,  but  sulphur  and  3*866  per  cent,  lead  in  the  form  of  acetate. 
—Ibid.  236. 
Sel  Boergrave,  a  Belgian  speciality,  was  found  by  Dr.  E.  Pfeiffer 
to  be  merely  coarsely  powdered  epsom  salt  ;  another  sample  con- 
tained between  2  and  3  per  cent,  of  citric  acid.  The  original  com- 
position, it  is  said,  requires  to  the  epsom  salt  the  addition  of  1  per 
cent,  of  chloride  of  sodium,  2  per  cent,  of  sulphate  of  potassa  and 
some  sugar. — Ibid.,  January,  1872,  26. 
Supersaturated  Solutions  of  Sulphate  of  Soda. — De  Coppet  uses 
the  anhydrous  salt,  which  has  been  heated  to  above  33°  C.  and  cooled 
again,  carefully  protected  from  the  dust  of  the  atmosphere.  The  salt 
is  added  in  small  portions  to  cold  water,  contained  in  a  vial,  which  is 
placed  in  a  water-bath  having  the  temperature  of  the  surrounding 
atmosphere,  so  that  the  temperature  of  the  solution  scarcely  varies 
during  the  experiment.  In  this  manner  the  author  succeeded  to  dis- 
solve at  14°  C.  35*8  anhydrous  sulphate  (Na2S04)  in  100  parts  of 
water,  while  the  saturated  solution  of  the  hydrate  (Na2SO4,10H2O), 
at  the  same  temperature,  contains  only  12*4  parts  of  the  anhydrous 
salt  in  100  of  water. — Journ.  de  Pharm.  et  de  Chim.,  1872,  Feb., 
117. 
Preparation  of  Pure  Muriatic  Acid. — Hager  states,  that  by  Bet- 
tendorfs  process,*  all  arsenic  is  precipitated  from  crude  muriatic 
acid  by  stannous  chloride,  but  if  a  trace  of  this  precipitate  is  poured 
into  the  retort  with  the  acid  the  distillate  again  contains  arsenic. 
*  Amer.  Journ.  Pharm.,  1871,  222. 
