2 
Bialyzed  Iron. 
Am.  Jour.  Pharm. 
Jan.,  1879. 
the  top  of  the  dish  ;  the  orifice  of  the  percolator  was  closed  with  a 
cork  ;  the  distilled  water  was  frequently  replenished  (at  first  every  two, 
and  afterwards  every  three  or  four  days).  In  forty  days  dialysis  was 
completed,  the  resulting  solution  of  iron  showing  no  acid  reaction,  and 
having  a  bland  taste.  It  measured  13  fluidounces,  and  contained  3*25 
per  cent,  of  solid  matter.  When,  by  spontaneous  evaporation,  the 
solution  had  been  concentrated  to  9I  fluidounces,  it  was  found  to  con- 
tain 5  per  cent,  of  solid  matter. 
When  it  is  taken  into  consideration  that,  with  the  above-described 
apparatus,  two  months  were  necessary  to  prepare  o,f  fluidounces.  of 
solution  of  dialyzed  iron,  it  will  not  at  all  be  surprising  if  it  was  con- 
cluded that  in  the  first  place  the  process  was  exceedingly  tedious  ;  and 
secondly,  it  would  be  more  profitable  to  purchase  the  preparation  if  no 
better  apparatus  could  be  constructed.  The  construction  of  a  some- 
what improved  dialisator  occupied  my  attention  for  some  time,  and 
fully  understanding  the  defects  of  the  old  one,  after  some  few  trials, 
an  improved  one  suggested  itself.  But,  at  the  same  time,  other  matters 
relating  to  dialysis,  which  were  not  well  understood  and  needed  some 
investigation,  suggested  themselves.  All,  put  in  the  form  of  questions, 
are  as  follows  : 
1.  Which  is  the.most  suitable  apparatus  for  preparing  the  solution 
of  dialyzed  iron  on  the  small  scale  ? 
2.  What  solution  of  iron  is  preferable  for  dialysis  ? 
3.  What  kind  of  parchment  paper  ought  to  be  used  for  a  good 
dialisator  ? 
4.  Does  the  use  of  distilled  or  rain  water  assure  a  better  and  medi- 
cinally purer  preparation  than  that  of  common  well  or  hard  water  in 
dialysis  ? 
In  answering  the  first  question,  it  will  not  be  maintained  by  the 
writer  that  the  apparatus  described  further  on  is  the  possibly  best  that 
could  be  devised,  but  that  up  to  the  present  writing  it  has  proved  to  be 
very  satisfactory  in  his  hands.  It  is  maintained  by  some  that  to  succeed 
with  dialvsis  the  liquid  in  the  dialisator  ought  not  to  reach  beyond  about 
a  half  inch  in  depth.  This  assumption  is  refuted  by  the  working  of 
this  apparatus,  since  in  it  the  liquid  may  have  a  depth  of  from  four  to 
six  inches,  and  probably  more,  without  perceptibly  retarding  the  process. 
The  apparatus  is  as  follows  :  A  half-gallon  glass  percolator,  3J  inches 
base  and  5J  inches  inside  diameter  at  the  top,  with  a  3-inch  funnel- 
shaped  projection  and  a  quarter  inch  orifice,  was  taken.    In  this  was 
