t?Airu'iS.arm'}    Recent  Literature  Relating  to  Pharmacy.  215 
RECENT  LITERATURE  RELATING  TO  PHARMACY. 
SOME  COLOR  REACTIONS  OF  TARTARIC,  CITRIC  AND  MALIC  ACIDS. 
According  to  E.  Pinerua  {Annates  de  Chimie  Analytique,  2,  66),  the 
reagent  for  producing  these  color  reactions  is  made  by  dissolving 
O-02  gramme  of  /9-naphthol  in  1  c.c.  of  sulphuric  acid,  specific  grav- 
ity 1-83. 
The  test  is  made  by  warming  cautiously  in  a  porcelain  capsule 
0-05  gramme  of  the  organic  acid  with  10  to  15  drops  of  the  reagent. 
Tartaric  acid,  when  thus  treated,  produces  a  blue  color,  which, 
under  the  gradual  action  of  heat,  becomes  a  pure  green.  If  to  the 
cooled  mixture  1 5  to  20  times  its  volume  of  water  are  added,  the 
green  coloration  passes  to  a  reddish-yellow. 
With  citric  acid  the  color  at  first  produced  is  an  intense  blue, 
which  does  not  become  green  on  the  further  application  of  heat,  and 
the  mixture  becomes  colorless  or  only  slightly  yellow  on  the  addi- 
tion of  15  to  20  times  its  volume  of  water.  If  the  citric  acid  contain 
only  a  small  quantity  of  tartaric  acid,  the  green  color  is  produced 
by  the  latter. 
Malic  acid,  when  treated  like  the  others,  produces  a  greenish-yel- 
low, quickly  passing  to  yellow.  The  addition  of  water  furnishes  an 
orange  color.  All  the  reactions  are  produced  quickly,  and  care  and 
judgment  must  be  used  in  applying  heat. 
THE  ALLEGED  CONVERSION  OF  CINCHONINE  INTO  CINCHONIDINE. 
Messrs.  B.  H.  Paul  and  A.  J.  Cownley  (Pharmaceutical  Journal, 
February  20,  1897)  have  investigated  the  alleged  conversion  of  cin- 
chonine  into  cinchonidine  and  reached  the  following  conclusions 
with  reference  to  their  experiments :  An  endeavor  to  corroborate 
Koenig  and  Hussmann's  statement  as  to  the  possibility  of  convert- 
ing cinchonine  into  cinchonidine  by  the  action  of  dilute  potash  was 
unsuccessful.  The  authors  stated  that  if  the  supposition  be  made 
that  the  base  obtained  was  really  cinchonidine,  it  must  be  presumed 
that  the  cinchonine  operated  upon  had  not  been  sufficiently  puri- 
fied. It  is  well  known  to  quinologists  that  the  cinchona  alkaloids 
are  very  prone  to  form  double  compounds  with  each  other,  either  as 
alkaloids  when  separating  from  various  solvents,  such  as  ether  and 
alcohol — the  latter  having  been  used  by  the  authors — or  as  salts 
from  aqueous  solutions.  Cupreine,  for  instance,  which  they  isolated 
from  Remijia  pedunculata,  forms  a  compound  with  quinine,  viz.:  homo- 
