Am.  Jour.  Pharm.) 
March,  1920.) 
Canthandes  Assay, 
157 
Table  V. 
Cc.  N/IO 
Germination 
Nitrogen 
Moisture 
Variety. 
HCl. 
%. 
%. 
%. 
Columbia  
  18.9 
71 
7  05 
5  .98 
Black  Eyebrow  
  18.9 
73 
7  •  75 
5  -54 
Chestnut  
  17-4 
82 
6 . 30 
6. 15 
  17-4 
51 
7  .92 
6.26 
Wilson  
  17.3 
81 
7  .92 
6.05 
82 
7-58 
5  ,5a 
Jet  
  170 
84 
9.26 
6.80 
Black  Sooty  
  16.8 
80 
7.42 
6.30 
Ito  San  
  16.7 
87 
7.98 
569 
Elton  
  15-9 
73 
7.84 
6.35 
Wisconsin  Black  
  157 
51 
8.26 
6.16 
Ebony  
  14.6 
67 
8.31 
6.41 
  141 
80 
7.89 
6. II 
Minn.  166  
  H-i 
51 
7.61 
6.12 
Manchu  
  136 
98 
8.09 
536 
It  will  be  seen  that  some  difference  exists  in  the  urease  activity 
of  different  varieties  of  soy  beans,  but  this  difference  appears  to 
bear  no  relation  to  the  germinating  power  of  the  seed  or  to  the  pro- 
tein content  of  the  latter.  In  fact  urease  may  be  demonstrated  in 
seeds  that  are  practicallly  dead,  as  in  the  case  of  sample  *'a,"  Table  IV. 
The  writer  is  indebted  tc  Mr.  J.  H.  Christ,  of  the  Farm  Crops 
Dept.  of  Iowa  State  College,  for  making  the  germination  tests. 
CANTHARIDES  ASSAY. 
By  Louis  Du  Bois, 
new  brunswick,  n.  j. 
The  U.  S.  P.  prior  to  the  present  IX  edition,  contained  no  standard 
for  cantharides  and  no  method  for  assay. 
For  years  we  have  been  using  in  this  laboratory  a  method  for  the 
determination  of  the  free  cantharidin  content  of  cantharides,  which 
had  been  evolved  from  sources  mentioned  elsewhere  in  this  article. 
This  method  has  appeared  to  give  satisfactory  results  both  in  the 
concordance  of  the  results  and  in  the  apparent  purity  of  the  resulting 
crystals. 
The  report  of  work  along  this  line,  as  given  herein,  is  by  no  means 
final,  but  it  has  been  considered  advisable  to  publish  it  for  the  ob- 
vious reason  that  the  U.  S.  P.  method  now  official  and  the  results 
from  its  use  seem  to  be  so  unsatisfactory  in  our  hands  that  we  believe 
the  matter  has  not  been  given  the  attention  it  deserves. 
