^'Ma^ch.fm'"''}         Commercial  Tartar  Einetic.  135 
acid.  The  detection  of  the  butyrate  in  the  salts  was  by  the  odor,  this 
becoming  more  or  less  apparent,  depending  on  the  quantity,  on  boil- 
ing the  solution  for  half  an  hour  in  the  test  for  formate. 
Acetic  Acid  within  the  last  few  years  has  been  made  by  a  modifi- 
cation of  the  process  first  in  use,  consisting  in  carefully  regulating  the 
temperature  which  is  maintained  between  150°C  and  162°C.  The 
yield  of  acetic  acid  is  as  great  as  if  the  wood  were  heated  to  a  higher 
temperature  while  at  the  same  time  it  is  free  from  the  empyreumatic 
odor. 
As  the  acids  examined  could  not  be  vouched  for  as  made  by  this 
modification,  a  sample  was  furnished  me  by  Mr.  Wallace  Procter. 
The  amount  of  formic  acid  in  it  was  lower  than  in  the  other  acids,  but 
the  method  of  analysis  showed  the  presence  of  0.017  per  cent. 
From  this  may  be  inferred  that  formic  acid  is  a  product,  in  larger 
quantity,  of  the  destructive  distillation  of  wood  at  higher  tempera- 
tures, and  that  on  the  temperatures  to  which  the  wood  was  heated 
may  depend  the  variable  quantities  of  formic  acid. 
To  purify  acetic  acid,  this  decomposition  of  the  formic  acid  may  be 
made  use  of ;  after  estimating  the  quantity  present,  the  proper  pro- 
portions of  mercuric  chloride  and  Rochelle  salt  can  be  added,  the 
mixture  boiled  for  half  an  hour  and  the  pure  acetic  acid  distilled  off. 
COMMERCIAL  TARTAK  EMETIC. 
By  Kaspak  Ho-rner,  Ph.G. 
Abstract  from  a  Thesis. 
Three  different  samples  were  procured  and  examined  according  to 
the  United  States  Pharmacopoeia.  All  the  samples  when  ignited  left 
a  black  residue  having  an  alkaline  reaction.  The  aqueous  solution 
was  precipitated  on  the  addition  of  hydrochloric  acid,  but  no  precipi- 
tate was  observed  if  tartaric  acid  had  been  previously  added.  The 
acidulated  solution  gave  an  orange  red  precipitate  with  sulphuretted 
hydrogen.  The  absence  of  sulphate,  chloride,  calcium  and  the  heavier 
metals  was  ascertained  in  a  one  per  cent,  solution  acidulated  with 
acetic  acid,  by  testing  with  barium  chloride,  silver  nitrate,  ammonium 
oxalate  and  potassium  ferrocyanide  and  the  absence  of  arsenic  by 
testing  with  strong  solution  of  soda  in  the  presence  of  aluminium. 
While  the  three  samples,  thus  tested,  answered  to  the  requirements 
of  the  Pharmacopoeia,  a  difference  was  observed  in  their  solubility  in 
