40 
The  Nutrition  of  Plants. 
f  Am.  Jour  Pbarm. 
\     January,  1896. 
rich  in  asparagine,  and  tried  to  nourish  them  with  organic  materials, 
repeatedly  making  microscopical  tests  in  the  usual  way  with  alcohol, 
as  described  by  Borodin,  Pfeffer  and  others,  and  finally  determining 
the  amount  of  asparagine  still  present  by  crystallization,  according 
to  E.  Schulze's  method.1  Either  methyl  alcohol,  glycerin  or  glu- 
cose was  used  as  organic  nutrient  in  solution  along  with  calcium 
sulphate.2  Every  seventh  or  eighth  day,  this  solution  was  replaced 
for  a  day  by  one  containing  0  5  per  mille  each  of  the  two  potassium 
phosphates,  and  of  hydrated  magnesium  sulphate,  so  as  to  furnish 
the  necessary  mineral  matters.  The  cotyledons  were  cut  off  at  the 
beginning  of  the  experiment,  in  order  to  prevent  further  formation 
of  asparagine  by  decomposition  of  the  reserve  proteids.  A  control 
experiment  was  made  at  the  same  time  with  soya  shoots  kept  in 
water,  in  which  an  asparagine  determination  was  made  just  before 
the  other  shoots  were  placed  in  their  nutrient  solutions,  and  again 
in  others  at  the  time  when  the  shoots  under  investigation  were 
analyzed. 
The  soya-beans  were  soaked  in  water  on  March  7th,  sown  on 
moist  sawdust  the  next  day  and  kept  in  the  dark.  In  four  days,  at 
rather  low  temperatures,  the  seeds  had  germinated  and  the  roots 
riad  reached  the  length  of  2-3  cm.  At  this  time  I  tested  the  tips 
of  several  roots  microscopically  for  asparagine,  and  found  only 
doubtful  traces ;  but  when  the  roots  had  become  6  cm.  long,  the 
presence  of  a  moderate  quantity  was  easily  recognized.  At  this 
time  the  young  plants  were  placed  in  water  on  a  wire  net. 
After  the  length  of  the  entire  plants  had  reached  20-27  cm., 
and  the  stem  and  the  root  had  been  found  to  be  rich  in  asparagine, 
by  microscopical  tests,  a  portion  of  the  shoots  was  placed,  on  April 
1st,  (a)  in  a  1  per  cent,  solution  of  methyl  alcohol  mixed  with  one- 
tenth  of  its  volume  of  saturated  gypsum  solution ;  (b)  in  glycerin3 
solution  of  I  per  cent,  with  gypsum,  and  (c)  in  glucose  solution,  the 
cotyledons  of  all  the  shoots  having  now  been  removed. 
Whenever  the  solutions  became  turbid  from  bacterial  growth,  they 
1  Landw.,  Jahrbuch,  1888,  pp.  688  and  701;  also  1880,  p.  14. 
2  In  some  trials  I  made  use  of  sodium  acetate  and  tartrate,  but  not  with 
satisfactory  results,  perhaps  because  the  conditions  were  not  favorable. 
3  Preliminary  experiments  had  convinced  me  that  a  solution  of  10  per  cent,  or 
even  of  5  per  cent,  glycerin  is  not  adapted  for  the  further  development  of  the 
plant.    Indeed,  in  the  10  per  cent,  solution  the  shoots  died  after  two  days. 
