132  Minutes  of  the  Pharmaceutical  Meeting.  {^"^Afcs^ys.^'"'' 
tion  through  a  piece  of  hide,  gives  up  to  it  all  its  tannir,  whilst  the  rest  of  the  dis- 
solved matters  pass  through  the  animal  tissue.  The  authors  have  satisfied  them- 
selves by  direct  experiment  that  the  matters  which  may  accompany  the  tannin,  such 
as  saccharine  and  gummy  substances,  organic  salts  of  potash,  lime,  magnesia,  &c., 
are  not  retained  by  the  hide.  On  evaporating  to  dryness  equal  quantities  of  the 
solution,  filtered  and  unfiltered,  and  deducting  the  weight  of  the  former  residue  from 
that  of  the  latter,  we  find  the  exact  weight  ol'  the  tannin  absorbed  by  the  hide.  As 
an  example,  50  grms.  of  oak-baak,  ground  in  a  coftee  mill,  are  exhausted  with  boil' 
ing  water,  so  as  to  make  up  250  c.  c.  of  liquid.  A  piece  of  hide,  free  from  hair, 
and  previously  softened  in  water,  is  stretched  over  a  small  zinc  drum  of  about  o'o6 
metre  in  diameter,  and  secured  in  its  place  with  a  copper  wire.  The  opposite  eiid 
of  the  dram  forms  a  tube,  to  which  is  attached  a  tube  of  caoutchouc  from  1*5  to 
2  m.  in  length,  and  terminating  above  in  a  funnel.  Into  this  is  poured  the  solution 
of  the  sample.  The  first  4  or  5  c.c.  of  the  filtrate  are  rejected  because  they  con- 
tain certain  albumenoid  matters  expelled  from  the  hide  by  displacement.  After 
having  thus  collected  by  filtration  a  certain  quantity  of  liquid,  25  c  c.  of  the  filtrate 
are  evaporated  to  dryness  at  100°,  and  also  25  c.c.  of  the  unfiltered  solution  j  we 
have  then — • 
Weight  of  tannin  and  foreign  matter,        ....        0465  grm. 
Weight  of  foreign  matter  alone,  .        .        .        .        .    0175  " 
©■290 
being  the  weight  of  tannin  present  in  25  c.c.  of  liquor.  The  total  volume  of  this 
liquor  being  known,  and  the  amount  of  bark  from  which  it  is  obtained,  the  per- 
centage of  tannin  in  the  latter  is  found  by  a  very  simple  calculation. — Chem  Ne-ivs 
[Lon.]j  Dec.  24,  1874,  from  Bull,  de  la  Soc.  Chim.  de  Parisy  Nos.  6  and  7,  Oct.  5,  1874. 
W^m  OF  THE  PHylf/CEUTICAL  MEETIf, 
The  fifth  meeting  of  the  session  was  held  February  the  i6th,  1875,  the  President, 
Dillwyn  Parrish,  in  the  chair.  The  Minutes  of  the  previous  meeting  were  read  and 
approved. 
The  following  presentations  were  made  to  the  Cabinet  and  Library,  and  the 
thanks  of  the  College  awarded  to  the  donors  : 
From  A.  W.  Miller,  M.  D.,  a  handsome  specimen  of  white  grape  sugar  ;  also, 
swimming  bladders  of  weak  fish  or  ocean-trout,  Otolithus  regalis ;  from  Wilson  H, 
Pile,  M.  D.,  two  hydrometers  made  without  the  usual  bulb,  this  shape  permitting  them 
to  be  introduced  into  bottles,  etc.  ;  from  Prof  Remington,  Armstrong's  Graduated 
Plaster  Apparatus — a  covenient  instrument  for  measuring  correctly  the  size  of 
plasters  and  preserving  a  straight  edge — consisting  of  a  board  with  two  graduated 
squares,  having  bevelled  edges,  controlled  by  side  pieces  and  set  screws  5  from  the 
American  Pharmaceutical  Association,  a  copy  of  their  Proceedings,  vol.  xxii,  1874  j 
from  H.  N.  Rittenhouse,  the  Ninth  U.  S.  Census  Report  in  four  volumes. 
