140 
PIPERIC  ACID. 
The  authors  do  not  decide  whether  the  acid  contains  22  or  24 
equivs.  of  hydrogen.  From  the  large  number  of  equivalents  of 
hydrogen,  and  its  small  per-centage,  the  analyses  furnish  little 
help  in  the  decision.  Analogy  with  other  acids  renders  24 
equivs.  more  probable,  but  the  decomposition  of  piperine  points 
rather  to  22.  They  also  consider  the  acid  to  be  bibasic,  on  the 
ground  that  if  monobasic,  it  would  contain  an  uneven  number 
of  equivalents  of  carbon. 
Piperate  of  soda  is  obtained  by  dissolving  the  acid  in  boiling 
caustic  soda  ;  on  cooling,  the  salt  is  deposited  as  a  white  crystal- 
line powder.  It  is  so  insoluble  in  cold  water  that  it  might  serve 
as  a  test  for  soda. 
Piperate  of  ammonia  is  formed  by  mixing  concentrated 
aqueous  ammonia  with  the  acid,  filtering  and  allowing  to  stand. 
It  crystallizes  in  colorless  brilliant  plates  which  strongly  resem- 
ble cholesterine.  Exposed  to  the  air  it  decomposes,  ammonia  is 
given  off,  and  the  substance  becomes  yellow  from  separation  of 
acid. 
Piperic  acid  forms  with  baryta  and  lime  insoluble  salts.  It 
also  combines  with  the  metallic  oxides  to  form  salts  which  are 
mostly  insoluble.  Piperate  of  piperidine  forms  colorless  lamellar 
crystals  of  splendid  silken  lustre.  On  exposure  to  the  air,  it 
undergoes  a  similar  decomposition  to  the  ammonia-salt.  Piperic 
ether  forms  colorless  crystalline  plates.  It  melts  at  158  to 
160°  F.,  and  decomposes  at  a  higher  rate  of  temperature  with 
the  production  of  a  horrible  acroleine  smell. 
The  treatment  of  alkaloids  with  alcoholic  potass  appears  to 
afford  an  important  means  of  arriving  at  their  constitution. 
Preliminary  experiments  with  other  alkaloids,  especially  cincho- 
nine,  show  that  the  decomposition  is  different  to  that  by  fusing 
them  with  alkalies.  And,  as  the  action  is  less  energetic,  it  may 
be  expected  that  the  products  obtained  stand  in  simpler  relation 
to  the  bodies  from  which  they  are  obtained, — -Chem.  Craz.,  Jan. 
1,  1858,  from  Journ.fiir  Prakt.  Chemie* 
