of  the  Ashes  of  Plants. 
533 
In  the  proportion  of  water  this  table  exhibits  very  considerable 
variation ; such  a result  would  naturally  follow  from  the  very 
different  periods  of  the  spring  and  summer  in  which  the  specimens 
were  collected,  and  would  no  doubt  be  found  in  two  grasses  of 
distinct  varieties  collected  from  one  spot  and  on  the  same  day. 
It  will  be  seen,  however,  that  with  very  little  exception  the 
grasses  which  come  early  into  flower  contain  the  most  water. 
This  circumstance,  which  is  of  importance  in  relation  to  the 
mineral  composition  of  the  grasses,  will  be  best  seen  by  grouping 
the  specimens  in  the  order  of  their  collection,  which  is  done  in 
the  following  table  :* — 
Date 
Water 
Ash  per 
Water 
Ash  on 
wet 
of 
Collection. 
per 
Cent. 
wet  sub- 
stance. 
per 
Cent. 
sub- 
stance. 
Bromus  mollis  . . 
May  8 
76-62 
1-36 
Anthoxanthum  odo-1 
ratum  . . . J 
May  25 
80-35 
1-24 
1 Mean  of  the  first! 
79-08 
1-58 
Poa  annua  . 
May  28 
79-14 
•59 
[ tour  specimens/ 
Alopecurus  pratensis 
June  1 
80-20 
1 *55 
J 
Lolium  perenne 
June  8 
71-43 
2-15 
\ 
Annual  rye-grass 
June  8 
79-14 
1-99 
1 Mean  of  the  four! 
71-93 
1-84 
Poa  pratensis  . . 
June  11 
67-14 
1-65 
j specimens  . / 
Dactylis  glomerata 
June  11 
70-00 
1-59 
) 
Festuca  duriuscula 
June  13 
69-33 
1-66 
Poa  trivialis 
June  18 
73-60 
2-20 
1 Mean  of  the  fourl 
66-31 
2-09 
Cynosurus  cristatus 
June  2 1 
62-73 
2-38 
f specimens  . j 
Bromus  erectus 
June  23 
59-57 
2-11 
J 
Holcus  lanatus 
June  29 
69-70 
1-93 
Avena  pubescens 
July  11 
61-50 
2-01 
1 Mean  of  the  four! 
61-81 
2-13 
Hordeum  pratense  . 
July  1 1 
58-85 
2-33 
[ specimens  • / 
Plileum  pratense 
July  11 
57-21 
2-26 
] 
Here  it  will  be  seen,  that  although  the  progression  from  very 
watery  specimens  in  the  month  of  May  to  much  drier  grasses  in 
June  and  July  is  not  altogether  regular,  yet  it  is  well  marked. 
Thus,  whilst  four  specimens  of  grass  collected  between  the  first 
and  last  week  of  May  afford  on  an  average  only  21  per  cent,  of 
dry  matter  ; other  four  specimens  collected  during  the  two  early 
weeks  of  J uly  contain  on  an  average  38  per  cent,  of  dry  matter, 
or  nearly  double.  Practically  it  is  known  to  be  the  case  that 
the  early  grasses,  valuable  as  they  are  for  spring  food,  do  not 
afford  the  same  weight  of  hav  as  those  which  come  into  flower  at 
a more  advanced  period  : so  that  in  calling  attention  to  this  cir- 
cumstance we  are  merely  enunciating  in  another  form  a well- 
known  truth. 
* The  whole  series  of  rabies  were  constructed  aljihabetically  before  the  advantage  of 
an  arrangement  in  the  order  of  collection  was  perceived.  Circumstances  would  not 
allow  of  their  reconstruction. 
