474 
Calcium  Oxalate  Crystals. 
/ Am.  Jour.  Pharm. 
X     October,  1901. 
pharmacopceial  drugs.  These  frequently  are  so  modified  in  form 
that  they  are  of  an  elongated  or  irregular  hexagonal  shape.  The 
crystals  of  this  group  are  sometimes  mistaken  for  silicon1.  Owing  to 
the  fact  that  the  lumen  of  the  cell  in  some  instances  is  completely 
filled  by  the  crystal  and  the  inner  wall  having  the  contour  of  the 
crystal,  it  is  impossible  by  simply  using  hydrochloric  acid  to  deter, 
mine  whether  the  crystal  has  been  dissolved  or  not.  This  group 
of  crystals  is  found  in  the  following  drugs  and  in  the  sizes  given  : 
Calumba,  about  15  microns  in  stone  cells. 
Cardamomum,  10-25  microns. 
Coca,  3-10  microns. 
Eucalyptus,  15-25  microns. 
Frangula,  5-20  microns. 
Gelsemium,  15-30  microns. 
2  Granatum,  about  15  microns. 
Hamamelis,  7-20  microns. 
Hyoscyamus,  about  10  microns  ;  single  or  in  twin  crystals. 
Krameria,  about  100  microns. 
2  Pimenta,  occasionally. 
Prunus  Virginiana,  20-30  microns. 
3  Quassia,  about  25  microns. 
2Quercus  alba,  10-20  microns. 
Quillaja,  35-200  microns. 
Rhamnus  purshiana,  5-20  microns. 
Senna,  10-20  microns. 
Uva  Ursi,  7-10  microns. 
Vanilla,  7-35  microns. 
2  Viburnum  opulus,  15-30  micron. 
2  Viburnum  prunifolium,  occasionally. 
Xanthoxylum,  10-25  microns. 
3.  Crystal  Fibers. — In  quite  a  number  of  drugs  a  single  monoclinic 
prism  occurs  in  each  of  the  parenchyma  cells,  adjoining  the  schleren- 
chyma  fibers,  and  to  this  single  longitudinal  row  of  superimposed 
cells  the  name  crystal  fiber  has  been  applied.  They  occur  in  the  fol- 
lowing drugs,  the  size  of  the  individual  crystals  also  being  given: 
Calamus,  about  15  microns. 
Frangula,  5-20  microns. 
1  Silicon  never  occurs  as  a  cell  content  in  sharp  angular  crystals,  but  occurs 
either  in  more  or  less  elliptical  or  irregular  hollow  masses  or  in  more  or  less 
solid  irregularly  branching  masses. 
2  Rosette  aggregates  are  also  present  in  these  drugs. 
3  Cryptocrystalline  crystals  also  occur. 
