Am.  Jour.  Pharm.) 
March,  1920.) 
Notes  on  Soy  Bean  Urease. 
153 
these  are  problems  that  require  extensive  equipment,  long  training- 
and  special  aptitude,  but  they  constitute  only  a  small  portion  of  the 
field  which  is  everywhere  ripe  to  the  harvest,  and  in  which  the  hum- 
bler gleaner,  with  ruder  tools  can  labor  with  benefit  to  science, 
both  in  its  abstract  and  applied  phases. 
It  is,  as  I  said  in  the  beginning,  the  duty  of  all  to  help  in  collection 
of  data,  either  by  adding  new  facts  or  correcting  old  statements  or 
even  classifying  known  data,  and  rendering  them  more  easily  un- 
derstood or  more  accessible.  Research  should  be  undertaken  in- 
telligently, that  is,  with  some  clear  object  in  view.  It  is  true  that 
some  few  important  discoveries  have  been  made  by  what  seems  to 
be  accident,  but  it  will  be  found  that  in  most  cases  the  discoverer 
was  engaged  in  real  and  commendable  investigation,  and  was  not 
merely  working  at  random. 
NOTES  ON  SOY  BEAN  UREASE. 
By  Arthur  W.  Dox,  Ph.D., 
iowa  state  college,  ames,  iowa. 
An  enzyme  capable  of  decomposing  urea  into  ammonium  car- 
bonate was  discovered  in  soy  beans  by  Takeuchi^  in  1909.  Four 
years  later  MarshalP  worked  out  a  quantitative  method  for  the 
determination  of  urea  in  urine  by  means  of  soy  bean  extracts.  The 
method  consists  essentially  in  titrating  the  ammonia  formed  by  the 
action  of  the  soy  bean  extract  upon  the  urea  solution,  using  methyl 
orange  as  an  indicator.  Under  the  conditions  described,  the  re- 
action was  quantitative  in  three  hours.  A  slight  error,  amounting 
to  0.8  per  cent.,  due  to  carbon  dioxide,  was  considered  negligible 
in  clinical  work.  In  a  second  paper,  MarshalP  adapts  the  method 
to  the  determination  of  urea  in  blood,  collecting  the  ammonia  by 
aeration.  Later,  he^  studied  the  activity  of  soy  bean  extracts,  as 
affected  by  dilution,  acids,  alkalies  and  ethyl  alcohol. 
The  properties  of  soy  bean  urease  have  been  studied  extensively 
'  Jour.  Coll.  Agr.  Tokyo.,  i:  i,  1909. 
2  Jour.  Biol.  Chem.,  14:  283-90,  191 3. 
3  Ihid.,  15:  487-94,  1913. 
*  Ibid.,  17:  351-61,  1914. 
