216  The  Agricultural  Education  Exhibition,  1904. 
highest  sugar  ll’O,  and  lowest  5’8.  The  nitrogen  varied  to  an 
even  greater  extent.  No  definite  relationship  could  be  found 
between  the  amounts  of  the  different  constituents  present  in 
a root  ; each  varied  independently  of  the  rest.  It  was  thus 
possible  to  have  a high  sugar  and  nitrogen  content  in  the 
same  root  or  vice  versa. 
A set  of  swede  diagrams  showed  the  percentage  of  dry 
matter  and  sugar  in  seven  varieties  of  swedes  grown  at  seven 
different  stations,  three  in  the  eastern  counties,  and  four 
in  Scotland.  It  was  shown  that  the  effect  of  locality  on  the 
composition  of  the  swede  was  not  so  great  as  on  the  mangel. 
Taking  the  average  of  the  seven  varieties,  the  highest  in  dry 
matter  was  12  per  cent.,  and  in  sugar  8 per  cent.,  grown  on 
a light  sandy  loam  in  Norfolk  ; and  the  lowest  in  dry  matter 
was  10‘4  per  cent.,  and  sugar  6 per  cent.,  grown  on  a light 
loam  in  Norfolk. 
A common  turnip  diagram  showed  the  percentage  of  dry 
matter  and  sugar  in  seven  varieties  of  turnij)  grown  at  two 
stations.  Here  the  difference  in  composition  between  varieties 
is  much  less  than  in  mangels  or  swedes. 
III.  Essex  County  Council  Technical  Laboratories. — Dia- 
grams and  turfs  from  experimental  j)lots  in  Essex  illustrated 
the  value  of  phosphatic  manures  in  increasing  the  quantity, 
and  improving  the  quality  of  the  herbage  on  the  derelict  grass 
land  in  Essex.  The  experiments  demonstrated  that  nitrogen- 
ous manures  in  the  absence  of  phosphates  were  of  little  A'alue. 
Basic  slag  had  proved  to  l)e  the  best  manure.  Other  turfs 
illustrated  the  use  of  sulphate  of  ammonia  as  a weed  killer. 
A small  pinch  of  this  placed  on  each  plantain  found  growing 
in  a lawn  killed  the  plantain  without  injuring  the  grass  ; 
daisies  may  also  be  destroyed  in  the  same  way.  Specimens 
of  red  clover  showed  how  clover  sickness  is  capable  of  being 
cured  by  the  application  of  lime;  the  beneficial  effect  of  this 
alkali  was  such  that  three  crops  of  clover  had  been  grown  in 
two  years  on  land  })reviously  “clover  sick”  ; with  basic  slag  and 
kainit  similar  results  had  been  obtained,  enabling  clover  to 
be  successfully  grown  twice  in  three  years. 
Other  exhibits  illustrated  a comparison  which  has  been 
instituted  between  Scotch  potato  soil  and  the  soil  of  Essex. 
The  two  soils  were  found  to  be  very  similar  as  regards  potash, 
which  is  essential  to  the  successful  cultivation  of  the  j)otato  ; 
but  the  Scotch  soil  contained  more  lime,  ])hos{)horic  matter, 
organic  matter,  and  nitrogen  than  the  Essex  soil.  The 
