566 
VALERIANATE  OF  AMMONIA. 
tallization  of  mucic  acid,  and,  like  gum  tragacanth  and  indigen- 
ous gum,  it  gives  rise,  by  boiling  in  water,  to  a  new  soluble 
gUm' 
This  gum  is  generally  regarded  as  arabine;  I  thought  at  first 
that  it  should  rather  be  analogous  to  the  gummy  matter  which 
MM.  Biot  and  Persoz  obtained  by  boiling  8  parts  of  gum  Arabic 
in  17  i  parts  of  warm  water,  acidulated  with  2  parts  of  sulphuric 
acid,  a  matter  which  they  compared  to  dextrine ;  but  I  dare  not 
yet  express  myself  positively,  for  this  regenerated  gum  acts  at 
15Q°C.  (302°F.)  like  arabine  itself,  and  constantly  reproduces 
artificial  cerasine. 
The  question  might  perhaps  be  decided  by  examining  compara- 
tively the  rotatory  power  of  these  substances,  but  having  no  in- 
strument, I  have  not  yet  been  able  to  make  this  verification. — 
London  Chemist,  May,  1857,  from  Comptes  Rendus,  Jan.  26, 
1857. 
VALERIANATE  OF  AMMONIA. 
This  substance  appears  to  attract  considerable  attention,  as  a 
remedy  for  neuralgia,  and  has  been  the  subject  of  a  somewhat 
unseemly  squabble  among  certain  members  of  the  Parisian  faeulty ; 
but  with  this  we  have  no  concern.  When  we  first  saw  a  notice 
of  it  in  the  periodicals,  we  could  find  no  mention  of  its  mode  of 
preparation  ;  and  as  the  dose  spoken  of  was  by  spoonfuls,  mani- 
festly of  a  solution  of  unknown  strength,  we  were  thrown  on  our 
own  resources  to  prepare  it.  Accordingly,  we  mixed  equivalent 
solutions  of  valerianate  of  zinc  and  carbonate  of  ammonia,  and 
removing  the  carbonate  of  zinc  thus  formed  by  filtration,  evapo- 
rated the  filtered  liquid,  and  finding  that  it  would  not  crystallize, 
dried  and  powdered  the  residue.  We  found  this  to  be  a  very 
expensive  process,  the  product  being  considerably  less  than  what 
theory  would  lead  one  to  expect.  M.  Laboureur  being,  like  our- 
selves, without  a  guide,  has  also  been  experimenting ;  but  the 
process  which  he  adopted  was  to  pass  dry  ammoniacal  gas  through 
mono-hydrated  valerianic  acid,  when  he  obtained  a  product  per- 
fectly white,  and  confusedly  crystallized.  Its  composition  is, 
one  equivalent  of  valerianic  acid,  one  of  water,  and  one  of 
