THE  AMERICAN 
JOURNAL  OF  PHARMACY 
OCTOBER,  iqoi. 
CALCIUM   OXALATE   CRYSTALS  IN  THE  STUDY  OF 
VEGETABLE  DRUGS.1 
The  value  of  the  study  of  reserve  starch  grains  in  determining 
the  origin  of  certain  vegetable  foods  and  drugs  has  been  recognized 
for  a  number  of  years.  It  is,  however,  becoming  more  evident  that 
the  starch  grains  which  we  recognize  as  typical  and  say  are  charac- 
teristic of  certain  products  occur  in  a  relatively  small  proportion 
to  the  whole  number  of  grains,  i.  e.  the  spherical  and  ellipsoidal 
starch  grains  occur  in  all  starchy  products  no  matter  what  their 
origin  may  be  and  the  so-called  characteristic  grains  (as  the  angular 
grain  in  corn,  or  the  excentric  grain  with  characteristic  point  of 
growth  and  lamellae  in  maranta,  potato,  calumba,  etc.),  are  by  no 
means  so  numerous  as  is  commonly  supposed.  So  that, for  instance, 
an  examination  of  wheat-flour2  which  has  been  admixed  with  say, 
from  5  to  10  per  cent,  of  corn  meal,  reveals  in  a  microscopical  mount 
of  a  milligramme  of  the  material  but  two  or  three  typical  corn 
starch  grains;  and  even  though  the  admixture  is  about  25  per 
cent,  only  about  seven  typical  grains  will  be  found. 
On  the  other  hand  calcium  oxalate  occurs  in  crystals  of  definite 
form  and  size  in  a  large  number  of  drugs  and  in  only  a  compara- 
tively few  instances  is  there  a  distinct  variation  in  the  type,  as  for 
instance  in  Datura  stramonium  L.3 
1  Presented  at  the  St.  Louis  meeting  of  the'American  Pharmaceutical  Asso- 
ciation, September,  1901. 
2  Kraemer,  Jour.  Am.  Chem.  Soc,  1899,  p.  650. 
3Kraemer  in  Proc.  A.  A.  A.  S.,  1899,  p.  305. 
By  Henry  Kraemer. 
(47i) 
