T II 13 
CEYLON  MANUAL  OF  CHEMI- 
CAL ANALYSES. 
A HANDBOOK  OF  ANALYSES  CONNECTED  WITH  THE 
INDUSTRIES  AND  PUBLIC  HEALTH  OF  CEYLON  FOR 
PLANTERS,  COMMERCIAL  MEN,  AGRICULTURAL 
STUDENTS,  AND  MEMBERS  OF  LOCAL  BOARDS. 
By  M.  COCHRAN,  m.a.,  f.c.s. 
( Continued  from  page  669. ) 
CHARTER  IV.— TEA. 
PREPARATION  OF  TEA— ANALYSES  OF  BLACK  AND 
GREEN  TEAS— CHIEF  CONSTITUENTS  OF  TEA — 
UNPREPARED  TEA  LEAVES— RELATION  BETWEEN 
CHEMICAL  COMPOSITION  OF  TEA  AND  ITS  MARKET 
VALUE— ANALYSES  OF  TEAS  BY  BATTERSHALL 
AND  DAVIS— ANALYSIS  OF  CliYLON  TEA,  MEDIUM 
PLUCKING  AND  FINE  PLUCKING— ANALYSES  OF 
INDIAN  TEAS  BY  AMERICAN  CHEMISTS— DETER- 
MINATIONS OF  THEINE  IN  INDIAN  AND  CEYLON 
TEAS— TANNIN  IN  TEAS— TEA  PRUNINGS — CAL- 
CULATION OF  THE  AMOUNT  OF  FERTILIZING 
MATERIAL  REMOVED  PER  ANNUM  FROM  ONE  ACRE 
OF  SOIL  BY  THE  TEA  CROP— MANURING  OF  TEA 
— TABLES  OF  USEFUL  DATA  F9R  MANURING 
EXPERIMENTS— ANALYSIS  OF  LEAVES  OF  GRE- 
VILLEA  ROBUSTA— COMPARISON  OF  THE  IMPORT- 
ANT CONSTITUENTS  OF  PLANT  FOOD  IN  TEA 
LEAVES  AND  GREVILLEA  LEAVES. 
EA  is  the  prepared  leaf  of  Thea 
sinensis.  Its  use  appears  to 
have  been  first  known  in 
China,  where  it  was,  accord- 
ing to  some  authorities,  a 
general  article  of  diet  as 
was  not  till  the  17th  century 
that  tea  was  introduced  into  Europe. 
The  tea  plant  is  a hardy  shrub  which  flourishes 
in  latitudes  between  the  equator  and  40°. 
In  the  preparation  of  the  teas  of  commerce  the 
treatment  varies  to  a considerable  extent.  In 
China  there  are  four  pluckings  during  the  year, 
one  in  spring,  the  next  in  May,  the  third  in 
June,  and  the  fourth  in  August.  In  Ceylon, 
tea  plucking  goes  on  continuously  throughout 
the  year,  so  long  as  the  bushes  continue  to  flush 
freely.  The  flushing  usually  extends  over  a 
period  of  about  eighteen  months.  The  bushes 
are  then  pruned  down,  and  after  an  interval  of 
from  six  weeks  to  three  months  according  to 
weather,  the  bushes  again  begin  to  yield  crop, 
and  undergo  another  series  of  regular  pluckings 
at  intervals  of  about  ten  days. 
The  leaf,  after  having  been  withered,  is  rolled 
for  a shorter  or  a longer  time,  and  then  allowed 
to  ferment.  The  time  allowed  for  fermentation 
varies.  It  may  continue  for  three  hours,  or  no 
fermentation  may  be  allowed  to  take  place  other 
than  what  goes  on  while  the  tea  is  being  rolled. 
Finally  the  rolled  tea  is  dried  over  charcoal  fires, 
or,  as  is  now  almost  universal,  in  specially 
constructed  hot  air  driers.  The  made  tea  is 
separated  by  sieves  into  sizes  known  as  broken 
pekoe,  pekoe,  pekoe  souchong  and  coarse  leaf. 
The  processes  which  are  productive  of  chemical 
changes  in  the  leaf  are  the  withering,  the  rolling 
and  fermenting,  and  the  firing  or  drying. 
Green  tea  differs  from  black  in  the  treatment 
the  leaves  receive  at  the  factory.  In  the  case 
of  green  tea,  the  leaves  a few  hours  after  being 
plucked  are  roasted  for  a short  time.  They  are 
then  rolled  and  quickly  dried.  Under  this  treat- 
ment the  leaves  do  not  become  black  but  of  an 
olive  green  tint. 
The  following  analyses  according  to  Dr.  James 
Bell,  Director  of  the  Somerset  House  Chemical 
Laboratories,  may  be  taken  as  fairly  representing 
the  composition  of  black  and  green  teas  as  ini. 
ported  into  London.  The  black  is  represented 
by  a Congou  Tea  at  2*.  lOd.  per  pound,  and  the 
green  by  a Young  Hyson  at  3s.  per  pound. 
