ON  HIVE  SYRUP  AND  ON  DIALYSIS. 
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top  of  a  perpendicular  rock,  200  feet  high,  on  the  banks  of  the 
river  Ericht. 
Having  spent  several  hours  in  strolling  about  the  beautiful 
grounds,  the  company  assembled  in  a  group,  and  a  photograph 
was  taken  by  an  artist  of  Dundee.  After  this  a  sumptuous 
dinner  was  served  up  at  Craighall,  Mr.  Russell,  of  Dundee,  pre- 
siding. On  returning  home  we  stopped  at  Coupar  Angus, 
where  the  company  sat  down  to  tea  at  the  hotel  Royal. 
Thence  again  took  the  road,  reaching  Dundee  about  10  o'clock 
P.  M.,  all  highly  delighted  with  this  pleasant  trip.  Not  enough 
praise  can  be  awarded  to  the  Arrangement  Committee  of  Dun- 
dee for  the  manner  in  which  they  received  and  provided  for  the 
comfort  of  the  non-resident  members  of  the  Conference. 
Respectfully  yours, 
Albert  G.  Ebert. 
ON  HIVE  SYRUP  AND  ON  DIALYSIS. 
By  Ludwig  Riederer. 
In  your  March  number,  1867,  is  an  essay  "  On  Hive  Syrup," 
by  L.  W.  Gillespie,  Laboratory,  Dearborn  St.,  Chicago  (ex- 
tracted from  the  Druggists  Circular),  which  induces  me  to  make 
a  few  corrections  thereon,  because  the  erroneous  use  of  the  im- 
portant chemical  process  of  "  dialysis  "  would  produce  conse- 
quences not  to  be  foreseen ;  and  an  incorrect  remark,  made  in 
the  final  part  of  his  essay,  "  on  the  inaccuracy  of  the  process," 
tends  to  diminish,  in  undeserved  manner,  the  interest  for  this 
subject. 
Dialysis,  introduced  not  long  ago  into  science  by  Graham 
(Annalen  der  Chemie  and  Pharmacie  121,  63),  depends  on  the 
varying  relations  of  bodies  to  animal  membranes.  One  division 
of  bodies,  "  Crystalloids,"  are  able  to  pass  through  certain  mem- 
branes, if  in  contact  with  them  in  solution — the  other  part, 
"  Colloids,"  do  not  possess  this  quality.  All  crystallizable 
bodies  belong  to  the  first  part ;  to  the  second  those  not  able  to 
crystallize,  as  glue,  gum,  dextrin,  caramel,  tannic  acid,  albumen, 
extractive  matter,  hydrate  of  silicic  acid,  etc. 
The  membrane  must  be  a  colloidal  substance ;  for  example, 
