240  Kinic  Acid  in  Cranberry  Leaves.  {AmMa™'if9o.arm* 
ceptibly  present  in  the  largest  amount  in  bark  recently  collected,  and 
but  sparingly  in  many  of  the  older  commercial  barks.  That  the 
material  used  in  this  research  was  undoubtedly  that  of  the  inner 
bark  of  Quercus  alba,  I  feel  quite  sure  of  as  this  same  reaction  was 
observed  in  bark  obtained  in  quantity  from  a  reliable  source  and 
also  in  that  collected  by  myself.  Whether  this  fluorescence  is  a* 
character  of  the  tannin  or  a  decomposition  product  of  it,  cannot 
from  present  work  be  accurately  stated,  and  it  is  useless  to  fill  up 
the  gap  by  mere  speculation;  but  given  some  time  1  hope  to  be  able 
to  throw  some  light  upon  the  constitution  and  nature  of  this  tannin. 
ON  THE  PRESENCE  OF  KINIC  ACID  IN  THE  LEAVES 
OF  THE  AMERICAN  CRANBERRY  (VACCINIUM 
MACROCARPON,  A/TON). 
By  Edo  Claassen. 
In  Vol.  58,  page  322,  of  this  journal,  it  was  stated  that  a  calcium 
precipitate,  prepared  from  the  above  leaves,  was  preserved  for  fur- 
ther examination  in  regard  to  the  presence  in  it  of  kinic  acid,  and 
in  the  same  volume  also,  on  page  325,  there  was  announced  the 
preparation  from  this  precipitate  of  a  calcium  salt  in  beautiful  6- 
sided  plates.  After  having  been  prevented  for  a  long  time  to  con- 
tinue the  examination  of  these  crystals,  I  could  now  commence  the 
same  again  and  consider  their  shape  as  well  as  their  composition  (i.  e.t 
tfie  amount  in  them  of  water  and  calcium) — and  also  their  properties 
when  treated  by  heat.  As  was  already  mentioned  above,  the  crys- 
tals in  question  presented  themselves  as  6-sided  plates,  showing  in 
their  appearance  no  difference  whatever  from  the  forms  of  the  cal- 
cium kinate,  which  are  described  to  consist  either  of  a  combination 
of  the  much  predominant  basal  plane  o  P  with  the  orthorhombic 
prism  00  P,  or,  as  in  this  case,  of  the  same  combination  and  the 
planes  00  P  00,  the  last  ones  of  course  truncating  the  acute  angles 
of  the  prisms,  thus  forming  6-sided  plates,  which  are  bounded  by 
the  same  planes  and  have  accordingly  the  same  appearance  like  the 
crystals  on  hand. 
The  examination  of  these  crystals  in  regard  to  their  amount  of 
water  and  calcium  was  then  done  as  described  below.  Before  enter- 
ing, however,  into  any  particulars,  it  may  be  stated  that  the  crys- 
tals were  kept  for  three  years  in  a  paper  box  and  in  a  dry  place, 
and   consequently  did  have  the  best  opportunity  to  lose  some 
