GLEANINGS  FROM  GERMAN  JOURNALS. 
311 
bitter  taste ;  by  the  yellow  crystalline  sparingly  soluble  precipi- 
tate with  bichromate  of  potassa,  and  by  the  intense  violet  color 
of  the  chromate  of  strychnia,  produced  by  concentrated  sulphuric 
acid. 
2.  A  proper  modification  of  the  process  of  Stas  and  Otto  con- 
sists in  the  substitution  of  ether  by  benzin  or  chloroform  for  dis- 
solving the  strychnia. 
3.  Dragendorff's  observation  is  corroborated,  that  acidulated 
dark  colored  aqueous  solutions  yield  some  of  their  coloring  mat- 
ters to  benzin,  but  strychnia  is  dissolved  by  this  menstruum  only 
after  the  addition  of  alkali  in  excess. 
4.  Benzin  or  chloroform  is  readily  recovered  by  distillation ; 
amylic  alcohol — recommended  by  v.  Uslar  and  Erdmann — must 
be  evaporated. 
5.  To  detect  strychnia  in  different  mixtures,  the  methods  of 
Stas  and  Otto  are  recommended  ;  the  use  of  subacetate  of  lead 
and  sulphuretted  hydrogen  is  to  be  avoided. — Neues  Jahrbuch  f. 
Pharm.  1868.    Jan.  1—9. 
Reduction  of  Chloride  of  Silver.  Dr.  Grseger  recommends 
for  this  purpose  to  dissolve  the  silver  in  ammonia  and  add  from 
time  to  time  some  pieces  of  zinc;  the  gray  powder  is  washed 
and  digested  with  concentrated  muriatic  acid  until  it  becomes 
whitish,  when  it  is  washed  with  distilled  water  and  a  little  am- 
monia, whereby  it  becomes  perfectly  pure.  Nitrate  of  silver  in 
ammoniacal  solution  is  reduced  by  the  same  process;  if  it  contains 
copper,  it  is  advisable  to  leave  a  little  silver  solution,  so  as  to 
avoid  the  precipitation  of  copper. — Ibid.  9 — 14. 
Testing  Vinegar.  W.  A.  Herb  has  constructed  an  acetometer, 
consisting  of  a  small  tube  for  measuring  the  requisite  quantity 
of  vinegar,  and  a  burette  to  be  used  with  clear  lime  water  ;  every 
10  degrees  of  the  burette  indicate  1  per  cent,  acetic  acid. — Ibid. 
Febr.  89—92. 
The  constituents  of  Tormentilla  have  been  examined  by  Rem- 
bold.  The  tormentilla  red  has  the  same  composition  as  rhatany 
red  ;  it  is  obtained  by  boiling  the  tannin  of  tormentilla  with  sul- 
phuric acid,  and  appears  to  be  identical  with  the  red  of  chest- 
nuts, since,  on  being  fused  with  caustic  potassa,  proto-catechuic 
acid  and  phloroglucin  are  formed.    Kinovic  acid  is  obtained  from 
