47<5 
Calcium  Oxalate  Crystals. 
f  Am.  Jour.  Pharm. 
1     October,  1901. 
drique."  My  own  investigations  tend  rather  to  the  opinion  that 
they  are  in  the  nature  of  hemihedral  forms  of  monoclinic  crystals. 
This  view  is  strengthened  by  the  fact  that  monoclinic  prisms  occur 
in  neighboring  cells  in  the  same  plant  as  in  Datura  stramonium  L., 
Quassia,  etc.  Cryptocrystalline  crystals  are  found  in  the  following 
drugs : 
Belladonnse  folia. 
Belladonnse  radix. 
Cinchona. 
Phytolacca  radix. 
Quassia. 
6.  Membrane  crystals. — There  are  several  forms  of  crystals 
which  may  be  included  in  this  group.  The  so-called  Rosanoff 
crystals  1  consist  of  rosette  aggregates  attached  to  inward  protrud- 
ing walls  of  the  plant  cell.  These,  however,  do  not  concern  us  so 
much  as  the  large  monoclinic  crystals  which  have  a  membrane 
(called  by  Payen  "  tissu  special  ")  surrounding  them.  The  crystal 
first  appears  in  the  cell-sap  and  then,  in  the  protoplasm  around  the 
crystal,  numerous  oil  globules  appear;  later  some  of  the  walls  of 
the  cell  thicken  and  grow  around  the  crystal  which  they  finally 
completely  envelop.  Crystals  of  this  character  and  of  the  sizes 
given,  are  found  in  the  following  drugs: 
Aurantii  amari  cortex,  15-20  microns. 
Aurantii  dulcis  cortex,  20-30  microns. 
CARBOHYDRATE  CRYSTALS. 
While  calcium  oxalate  crystals  have  been  mistaken  for  crystalline 
sugars,  it  should  also  be  pointed  out  that  some  of  the  more  or  less 
soluble  carbohydrates,  as  hesperidin  and  inulin,  may  be  mistaken 
for  calcium  oxalate.  They  occur  in  either  sphere-crystals  or  irregu- 
lar spherical  aggregates  which  are  more  or  less  easily  soluble  in 
water.  They  are  found  in  buchu,  hedeoma,  inula,  lappa,  pyrethrum, 
taraxacum  and  triticum. 
DRUGS  WITH  LITTLE  OR  NO  CALCIUM  OXALATE. 
In  the  following  drugs  calcium  oxalate  crystals  are  either  wanting 
entirely  or  so  few  as  to  be  without  any  diagnostic  value:  Aconitum, 
apocynum,  arnicae   flores,   capsicum,  chirata,  cimicifuga,  colchici 
Rosanoff,  in  Bot.  Zeit  ,  1865,  p.  329. 
