Am.  Jour  Pharm.  \ 
August,  1889.  J 
Composition  of  Tragacanth. 
427 
converting  it  into  the  calcium  salt  (Kiliani,  Annalen,  ccv,  184).  The 
filtrate  was  evaporated,  and  the  galactose,  which  crystallized  from  the 
solution,  identified  by  converting  into  the  osazone. 
The  formation  and  decomposition  of  lactobionic  acid  confirm 
Fischer's  conclusions,  (1888,)  with  regard  to  the  constitution  of  milk- 
sugar. 
An  acid,  isomeric  with  lactobionic  acid,  can  most  probably  be  ob- 
tained from  maltose  by  the  process  described  above  ;  this  compound, 
on  inverting,  should  yield  gluconic  acid  and  dextrose. 
THE  COMPOSITION  OF  TE  AG AC ANTH . 
By  John  Ogle,  M.  P.  S. 
An  article  headed  "  The  Soluble  Gum  of  Tragacanth,"  by  Pro- 
fessor J.  M.  Maisch,  reprinted  from  the  American  Journal  of  Phar- 
macy, suggested  that  some  uncertainty  exists  as  to  the  composition  of 
this  drug.  The  statements  made  in  the  various  works  on  materia 
medica  referred  to  in  that  article  are  so  conflicting  that  it  was  felt  that 
another  investigation  would  not  be  out  of  place.  Accordingly 
an  examination  was  carried  out  with  the  object  of  determining 
the  amount  of  moisture  and  soluble  gurn  present ;  to  what  extent  the 
soluble  portion  resembles  gum  acacia ;  and  the  percentage  of  ash 
yielded. 
A  sample  of  fine  Syrian  tragacanth,  answering  to  the  " characters" 
of  the  Pharmacopoeia,  was  obtained  through  the  courtesy  of  Mr.  C. 
Umney.  Of  this,  5  grams,  maintained  at  a  temperature  of  100°  C. 
for  twenty-four  hours,  left  a  residue  weighing  4'054  grams,  the  loss  of 
•946  gram  being  equivalent  to  18 '92  per  cent,  of  moisture. 
The  dried  gum  was  powdered :  to  3  grams  of  the  powder  250  cc. 
of  distilled  water  were  added,  and  the  mixture  was  heated  to  80°  C. 
for  six  hours,  in  order  to  effect  disintegration.  To  the  resulting  semi- 
fluid mass,  which  was  too  viscid  to  allow  of  filtration,  distilled  water 
was  added  so  as  to  increase  the  volume  to  a  litre.  After  standing  for 
two  hours  the  fluid  was  thrown  upon  a  wet  filter,  when  a  bright,  col- 
orless solution,  neutral  to  test  paper,  was.  slowly  obtained.  100 
cc.  of  this  liquid,  representing  the  soluble  constituents  of  *3  gram  of 
the  dried  sample,  yielded  on  evaporation  a  transparent  residue  which 
weighed  *133  gram,  equal  to  44*33  percent,  of  soluble  gum  calculated 
