AMbeeURi;  m3RM'  {    Detection  of  the  Adulteration  of  Tea.  5  i  7 
this  hesperisic  acid  forms  a  lead  salt  insoluble  in  water,  and  a  calcium 
salt  soluble  in  water  and  precipitated  by  alcohol  from  aqueous  solu- 
tion ;  its  barium  salt  is  soluble  in  water.  The  acid  is  obtained  by 
treating  the  purified  calcium  salt  with  sulphuric  acid  and  ether ;  on 
evaporation  of  the  ether  the  acid  is  left  as  a  honey-like  mass,  which 
gradually  becomes  crystalline.  It  is  hexabasic  and  has  the  composi- 
tion C20H26O17,2H2O,  the  2H20  being  lost  at  100°. 
Action  of  Hydriodic  Acid  on  Hespe?*idene. — Hydriodic  acid  com- 
bines with  hesperidene,  forming  a  liquid  compound  partially  decom- 
posed by  distillation.  Attempts  to  synthesise  an  acid  containing 
eleven  proportions  of  carbon  by  acting  on  this  hydriodide  with  cyan- 
ide of  silver,  etc.,  met  with  little  success  :  it  was  also  found  impracti- 
cable to  add  hydrogen  on  to  hesperidene  by  the  joint  action  of  phos- 
phorus and  hydriodic  acid,  a  polymeride  boiling  about  250°  being  the 
sole  product. —  Pharm.  Journ.  and  Trans.,  October  18,  1873. 
ON  THE  DETECTION  OF  THE  ADULTERATION  OF  TEA 
Read  before  the  British  Association  for  the  Advancement  of  Science. 
By  A.  H.  Allen,  F.C.S. 
As  public  analyst  for  the  borough  of  Sheffield,  many  samples  of  tea 
had  been  brought  under  the  author's  notice,  chiefly  by  dealers  them- 
selves, in  order  to  guard  against  selling  tea,  which,  if  they  had  been 
analyzed  by  him  officially,  might  have  been  condemned  as  adulterated. 
The  analyses  of  tea  up  to  the  present  time  were  by  no  means  nume- 
rous ;  and  some  were  so  old  that  they  might  well  be  viewed  with  sus- 
picion. The  three  principal  constituents  of  tea  were  tannin,  gum, 
and  "woody  fibre,"  with  small  quantities  of  some  albumenoid  body, 
theina  (the  active  principle),,  coloring  matters,  chlorophyll,  essential 
oils,  &c.  The  proportions  of  these  found  by  different  analysts  varied 
very  much,  the  difference  evidently  depending  upon  the  methods  of 
determination  employed.  His  object  had  been  more  to  work  out  a 
technical  method  of  testing  teas  for  adulteration  than  to  establish  the 
actual  composition  of  genuine  tea.  The  estimations  that  had  been  made 
of  tannin  seemed  to  present  the  greatest  variations,  and  in  many  cases 
they  were  manifestly  wrong.  A  modification  of  Dr.  Hassall's  pro- 
cess, in  which  a  volumetric  solution  of  gelatin  was  used,  had  given 
him  very  concordant  and  reliable  results,  and  had  made  the  deter- 
mination of  tannin  in  tea  an  operation  of  a  rapid  and  tolerable  simple 
