168     EXPEEIMENTS  ON  THE  COMPOSITION  OF  WHEAT  GRAIN. 
ness  with  caustic  potash  from  tartar;  the  adhering  kaolin  having 
been  dissolved,  the  bars  were  washed  in  pure  water. 
They  were  divided  into  small  blocks  by  means  of  a  chisel  of 
tempered  steel.  As  the  hardest  chisel  leaves  traces  of  iron  on 
the  surface  of  the  silver,  the  small  blocks  were  digested  with 
warm  hydrochloric  acid,  pure  and  concentrated.  The  silver  was 
then  washed  with  ammoniacal  water,  and  lastly  with  water,  and 
heated  up  to  its  fusing  point  before  being  placed  into  a  well 
stoppered  bottle. 
I  procured,  at  a  single  easting,  2875  grammes  of  silver  of  an 
extraordinary  whiteness. 
I  will  subsequently  state  how  I  assured  myself  of  its  state  of 
purity ;  I  wish  first  to  describe  the  second  method  which  I  made 
use  of  to  procure  large  quantities  of  pure  silver. — London  Chem* 
Neivs,  Jan.  18,  1867. 
EXPERIMENTS  ON  THE  COMPOSITION  OF  WHEAT  GRAIN. 
By  A.  H.  Church,  M.A.  Oxqn.,  F.C.S. 
Professor  of  Chemistry  in  the  Royal  Agricultural  College,  Cirencester. 
The  influence  of  season,  climate,  manure,  etc.,  upon  the  com- 
position of  wheat  grain,  has  engaged  the  attention  of  many  scien- 
tific observers.  MM.  Boussingault,  J.  Pierre,  and  Keiset,  abroad, 
and  Messrs.  Lawes  and  Gilbert,  in  this  country,  have  added  sev- 
eral important  facts  to  our  knowledge  of  the  variations  in  the 
yield  and  quantity  of  corn  under  different  conditions  of  culture 
and  atmospheric  influence,  and  also  according  to  the  particular 
variety  of  seed  grown.  There  were  still  several  points  to  be 
cleared  up,  and  it  is  to  one  among  these  that  my  attention  has 
been  more  particularly  directed  since  the  autumn  of  1863.  It 
is  the  relation  of  the  density  of  the  seed  to  its  chemical  compo- 
sition, and  to  its  germinating  and  productive  powers,  that  I  have 
submitted  to  an  experimental  investigation.  The  first  portion 
of  my  results  has  been  already  published,*  and  a  brief  account 
of  those  more  recently  obtained  may  prove  of  interest  to  the 
readers  of  the  "Journal  of  Botany." 
Most  samples  of  dressed  wheat-grain,  if  carefully  examined, 
*  "  Practice  with  Science/'  part  i.  p.  101.    Longman,  1865. 
