732 
THE  TROPICAL  AGRICULTURIST. 
[June  i,  1893. 
It  will  be  observed  from  these  tables  or  analyses 
that,  in  the  case  of  young  leaves,  there  is  a re- 
markable decrease  from  May  to  November  in  the 
amount  of  theine,  the  proportion  in  May  being 
2-85  times  as  much  as  in  November,  while  old 
leaves  in  May  contain  less  than  young  leaves  in 
November.  The  tannin  in  young  leaves  gradu- 
ally increases  with  slight  fluctuations  from  May 
to  November,  while  the  tannin  in  old  leaves  in 
May  is  only  a little  above  the  average  of  the 
young  leaves.  The  considerable  decrease  in  the 
young  leaves  in  the  amount  of  crude  protein  and 
cellulose  &c.  and  the  considerable  increase  in  the 
ethereal  extract  as  the  year  advances  shew  that 
j-he  composition  of  the  tea  is  affected  to  a consider- 
able degree  by  season. 
It  will  also  be  observed  that  the  three  most 
important  elements  of  plant  food,  i.c.,  those  tha4 
are  most  readily  exhausted  from  the  soil,  and 
which  therefore  constitute  the  most  valuable  in- 
gredients of  manures,  viz.,  nitrogen,  phosphoric 
acid  and  potash  all  decrease  from  May  to  November, 
while  most  of  the  less  important  or  more  abun- 
dant constituents  soda,  lime,  magnesia,  oxide  of 
manganese,  peroxide  of  iron  and  sulphuric  acid  all 
increase.  Silica  and  chlorine,  however,  fluctuate 
in  an  indefinite  manner. 
In  Ceylon,  where  the  seasons  are  not  so  marked 
as  in  Japan,  at  least  in  respect  of  temperature, 
it  is  probable  that  tea  leaves,  plucked  in  different 
months,  would  exhibit  greater  uniformity  of 
composition. 
Relation  between  Chemical  Composition  and 
Market  value  oj'  Tea. 
Various  attempts  have  been  made  to  discover 
a relation  between  the  chemical  composition  of 
tea  and  its  market  value,  but  with  only  partial 
success,  one  reason  for  this  comparative  failure 
being  that  the  flavour  and  probably  also  the 
stimulating  effect  are  in  no  inconsiderable  degree 
due  to  the  very  small  quantity  of  essential  oil 
present,  which,  moreover,  is  an  ingredient,  the 
amount  of  which  it  is  very  difficult,  if  not  im- 
possible, to  determine  with  accuracy. 
The  following  table  of  analyses  from  Dr.  Jesse 
P.  Battershall’s  work  on  “ Food  Adulteration,” 
that  writer  says,  “exhibits  the  results  obtained 
by  the  examination  of  various  grades  of  Formosa, 
Congou,  Young  Hyson,  Gunpowder  and  Japan 
teas,  made  under  the  supervision  of  the  writer, 
by  Dr.  J.  F.  Davis-  It  will  be  noticed,  if  the 
same  varieties  of  tea  be  compared,  that,  with 
some  exceptions,  their  commercial  value  is 
directly  proportional  to  the  percentage  of 
soluble  ash,  extract,  tannin  anil  theine  com- 
pounds”. 
Following  the  table  of  American  analyses  by 
Battershall  and  Davis  is  a table  of  analyses  by 
the  author,  of  young  tea  grown  in  Ceylon  at 
medium  elevation,  about  2,400  feet. 
These  analyses  were  undertaken  partly  to  as- 
certain if  the  market  value  of  Ceyion  tea  bore 
any  relation  to  the  amount  of  extract,  tannin, 
theine  and  soluble  ash  present,  and  partly  to  as- 
certain if  there  were  any  marked  difference  in  the 
chemical  composition  of  tea  on  account  of  its 
having  been  harvested  after  the  methods  known 
as  medium  plucking  and  fine  plucking  respectively. 
By  ‘ ‘ medium  plucking”  is  understood  the  re- 
moval from  the  tree- branches  of  two  leaves  and 
one  leaf  bud.  By  “fine  plucking”  is  understood 
taking  only  one  leaf  and  one  leaf-bud.  The  six 
samples  of  tea  were  all  from  the  same  estate, 
which  was  land  that  had  been  previously  thirty 
years  under  coffee.  The  tea  bushes  were  exactly 
rive  years  old.  The  samples  were  valued  in  the 
usual  way  by  tasting  by  Mr.  James  A.  Henderson 
of  the  firm  of  Messrs.  Whittall  & Co.,  Colombo, 
who  had  not  seen  the  analyses  before  making  his 
valuation. 
