ss 
Tea. 
[  Am.  Jour.  Pharm. 
I    February,  1903. 
allowed  to  lie  for  a  time  spread  out  in  the  factory  after  being  gath- 
ered and  before  they  are  roasted  ;  (2)  that  they  are  tossed  about 
until  they  become  soft  and  flaccid,  and  then  left  in  heaps,  and  that 
this  also  is  done  before  they  are  roasted ;  (3)  that  after  being  roasted 
for  a  few  minutes  and  rolled,  they  are  exposed  for  some  hours  to 
the  air  in  a  soft  and  moist  state  ;  and  (4)  that  they  are  at  last  dried 
slowly  over  charcoal  fires.  The  differences  in  the  manufacture  of 
black  and  green  teas  are  therefore  most  marked,  and  I  think  fully 
account  for  the  difference  in  color,  as  well  as  for  the  effect  produced 
on  some  constitutions  by  green  tea,  such  as  nervous  irritability, 
sleeplessness,  etc." 
VI.  CHEMISTRY. 
As  in  the  case  of  coffee,  the  taste  of  tea  is  principally  due  to  an 
essential  oil  and  to  tannic  compounds.  The  oil  is  not  present  in  the 
fresh  leaf,  but  develops  in  the  curing  process  to  the  extent  of  -75 
per  cent,  of  the  weight  of  the  dried  leaves.  In  theine,  tannic  com- 
pounds  and  essential  oil,  the  tea-leaf  is  much  richer  than  the  coffee 
bean.  It  is  by  these  three  constituents  that  the  beverage  materials 
are  usually  compared  from  a  chemical  point  of  view.  The  differ- 
ences between  tea  and  coffee  are  shown  in  the  following  table  of 
analyses : 
Tea,  per  cent.  Coffee,  per  cent. 
Water  \  .  .  5       "  12  " 
Theine   3       "  1*75  " 
Caseitie   15       "  13  " 
Gum   18       "  9 
Sugar   3       "  6*5  " 
Starch  ...   trace  trace 
Tannin                                      ....  26*25  "  4  " 
Aromatic  oil                                         .  0*75  "  0*002 " 
Fat   4       "  12 
Fibre   20       "  35  " 
Mineral   5       "  67  " 
Such  analyses  are  only  partially  satisfying.  It  should  be  remem- 
bered that  it  requires  five  or  six  times  more  coffee  to  make  a  cup  of 
coffee  than  of  tea  to  mak  a  cup  of  tea.  Hence,  in  determining  the 
amount  of  theine  and  tannin  taken  into  the  stomach  with  these 
beverages,  the  liquors  themselves,  and  not  the  beans  and  leaves, 
should  be  subjected  to  analysis. 
In  the  following  table  black  and  green  tea  are  compared : 
