280  Mate,  or  Paraguay  Tea.  { Amjine,rx87h8arm' 
"American  Journal  of  Pharmacy,"  1877,  page  388.)  Of  each  sample 
of  mate,  finely  powdered,  10  grams  were  taken  and  separately  treated  ; 
first  by  percolation  with  petroleum  benzin  ;  this  removed  most  of  the 
green  coloring  matter  and  none  of  the  tannin,  as  the  percolate  upon 
evaporation  and  treatment  with  water  failed  to  give  to  the  proper 
reagents  any  indication  of  the  presence  of  tannic  acid.  The  mate  was 
removed  from  the  percolator,  and,  after  drying,  repacked  and  treated 
with  alcohol  of  seventy-five  per  cent,  until  the  percolate  passed  free  of 
color;  then  the  residue  was  removed  to  a  flask  and  boiled  with  several 
successive  portions  of  alcohol  of  the  same  strength,  the  several  tinc- 
tures mixed,  when  cold  filtered  and  the  filter  washed  with  alcohol. 
The  alcohol  was  then  driven  off  on  a  water-bath,  and  the  solution 
made  up  to  the  previous  measure  with  distilled  water,  and  a  slight 
excess  of  basic  acetate  of  lead  added,  which  threw  down  an  abundant 
bright  yellow  precipitate.  This  was  well  washed  with  distilled  water, 
decomposed  by  sulphuretted  hydrogen,  and  after  heating  on  a  water- 
bath  to  remove  excess  of  the  sulphuretted  hydrogen,  the  sulphide  of 
lead  was  removed  by  filtration  and  the  filter  well  washed  with  distilled 
water.  The  filtrate  was  a  clear  solution  of  an  intense  yellow  color, 
and  upon  being  evaporated  on  a  water-bath  to  dryness  yielded  a  light- 
brown  amorphous  mass,  fusible  by  heat,  and  which,  when  powdered, 
was  of  a  buff  color  ;  its  solution  strongly  reddens  litmus  paper.  The 
quantity  obtained  from  each  sample  is  shown  in  table  No.  I.  It  will 
also  be  observed  that  those  samples  containing  the  most  tannin  con- 
tained the  least  caffeina.  The  following  is  a  description  of  the  beha- 
vior of  this  peculiar  tannic  acid  with  different  reagents  : 
With  ferric  salt  it  gives  a  bright  green  at  first,  turning  to  brown  on 
standing  and  a  brown  precipitate  ;  with  ferrous  salts  no  change  at  first, 
becomes  green  on  standing  and  deposits  very  dark  olive  precipitate  ; 
Wiith  fixed  alkalies  transparent  dark  yellow  color,  unchanged  by  heat, 
no  precipitate  •,  lime  water  gives  a  transparent  pure  yellow,  and  on 
standing  a  grayish  brown  precipitate  ;  aqua  ammoniae  gives  a  transparent 
intense  yellow,  almost  brown,  no  precipitate  ;  acetate  of  copper  gives 
a  light-green  precipitate,  not  soluble  in  excess  of  precipitant 5  sulphate 
of  copper  gives  no  precipitate  in  the  cold,  but  when  heated  a  brown 
precipitate  is  given  ;  ammonio-sulphate  of  copper  slowly  precipitates 
in  the  cold,  and  at  once  if  heated  ;  nitrate  of  silver  is  reduced  by  the 
