ON  HIVE  SYRUP  AND  ON  DIALYSIS. 
511 
which  would  have  111.1016  not  only  a  very  inefficacious  syrup,  but 
also  liable  to  spoil,  and  the  whole  process  would  have  been  for 
nothing. 
As  the  accurate  results  obtained  by  dialysis  are  known,  and 
not  contestable,  the  reproach  made  to  the  method  recoils  upon 
Mr.  G.  himself,  and  it  is  very  strange  that  Mr.  G.  should  throw 
aside  the  method  of  dialysis  after  having  made  but  one  experi- 
ment, and  this  one  full  of  faults.  A  little  more  self-instruction 
in  the  principles  of  dialysis  would  not  have  been  superfluous, 
and  would  have  spared  this  criticism. 
New  York,  Sept,  1867. 
Note  by  the  Editor.— An  apology  to  our  readers  is  per- 
haps due  that  this  paper  was  reprinted  without  comment,  as  it 
is  certainly  obnoxious  to  the  criticism  of  Mr.  R.,  but  its  transfer 
was  made  under  circumstances  that  may  excuse  the  neglect. 
Assuming  as  fact  the  statement  of  Mr.  Riederer  that  porous 
earthenware  possesses  no  dialytic  properties,  it  is  a  curious  re- 
sult that  Mr.  Gillespie  found  colloids  in  his  diffusate  without  any 
(except  a  trace)  of  polygalic  acid,  a  result  directly  the  reverse 
of  the  dialytic  action  of  Graham's  septa,  (starch,  parchment,  etc.) 
We  have  made  no  experiments  with  senega  to  test  this  point  and 
mention  it  in  passing  as  at  least  curious  and  worthy  of  notice, 
for  if  it  be  true  that  such  a  septum  as  porous  earthenware  will 
separate  colloidal  matter  by  osmotic  action  from  well  marked 
active  principles  like  that  of  senega,  it  may  be  employed  in  the 
very  case  in  question  with  propriety.  In  thus  speaking  it  is 
with  the  hope  that  Mr.  Gillespie  (who  appears  to  have  misun- 
derstood the  process  of  dialysis)  may  resume  the  subject  and,  in 
view  of  the  criticism  of  Mr.  Riederer,  repeat  his  experiments 
with  parchment  paper  or  other  colloid  septum,  as  well  as  with 
porous  earthenware,  and  give  us  his  results,  which  may  prove 
interesting  if  he  corroborates  his  own  statement.  In  the  period 
of  twelve  hours,  during  which  this  proof  has  been  in  our  hands, 
we  dialysed  a  mixture  of  an  ounce  of  Syrupus  senega  U.  S.  P., 
mixed  with  twice  its  bulk  of  water,  in  contact  with  a  pint  of 
water,  using  good  English  parchment  paper  for  a  septum.  The 
diffusate  acquired  a  light  yellowish  color  and  the  odor  of  senega, 
