1 64  Tartaric  Acid.  {AmApru;imrm* 
tillation  from  the  leaves  it  cannot  contain  a  cyanide,  and  the  free 
hydrocyanic  acid  will  not  cause  a  precipitate.  Very  likely  the  water 
was  prepared  by  means  of  magnesia,  in  which  case  it  must  have 
contained  magnesium  cyanide  which  would  precipitate  morphine. 
It  is  proper  to  add  that,  in  the  paper  quoted,  Prof.  Fluckiger  has 
also  shown  that  berberine,  quinine,  cinchonine  and  strychnine  like- 
wise ^lo  not  form  cyanides  under  similar  circumstances. 
TARTARIC  ACID! 
By  Fred.  H.  Smith. 
Contribution  from  the  Chemical  Laboratory  of  the  Philadelphia  College  of  Pharmacy. — 
No.  69. 
Read  before  the  Philadelphia  College  of  Pharmacy  at  the  Pharmaceutical  Meeting, 
March  18. 
It  has  been  noticed  that  the  text  books  differ  in  their  statements 
about  the  melting  point  of  tartaric  acid.  Many  give  1 3  5 0  C,  which 
was  obtained  by  Schiff  in  1863  (Annalender  Chemie,CXX.V ',  p.  133). 
In  a  number  of  the  works  published  since  that  time,  the  melting  point 
is  given  as  1700  C,  notably  in  Watt's  Dictionary  (vol.  5,  p.  675),  which 
gives  1700  to  1800  C.  as  the  temperature  at  which  the  acid  melts. 
My  observations  have  differed  from  all  of  them,  and  in  order  to 
obtain  more  light  upon  the  subject,  I  purchased  seven  samples  of 
the  acid  from  different  retail  stores,  six  of  which  were  in  the  form 
of  powder,  the  other  in  crystals. 
The  melting  points  were  taken  and  resulted  as  follows  : 
A 
B 
c 
D 
n 
F 
G 
Crystals. 
Melting  Point,  . 
162.80 
163-5° 
159-1° 
163-5° 
163-5° 
167-5° 
162 
These  experiments  were  performed  with  a  corrected  Yale  ther- 
mometer. 
It  was  thought  that  possibly  the  variation  in  the  melting  points 
might  in  some  respect  be  due  to  adhering  moisture.  Consequently 
a  number  of  the  samples  were  dried  at  a  temperature  between  80 
and  900  C.  for  about  an  hour,  the  amount  of  loss,  however,  was  not 
over  -005  to  nearly  5  gms.  of  the  acid.  After  drying,  the  melting 
points  were  again  determined,  but  did  not  vary  perceptibly  from  the 
