318  PHABMACEUTICAL  GLEANINGS  AND  NOTICES. 
oxide  of  iron  and  alumina,  are  placed  on  the  dialyser,  when  free 
hydrochloric  acid  is  diffused  through  the  septum,  while  the 
hydrated  oxide  remains  on  the  dialyser.  It  is  also  probable 
that  the  action  of  medicines  when  taken  into  the  stomach  is 
influenced  by  their  relations  as  colloids  or  crystalloids,  some 
being  transfused  through  the  coats  of  that  organ,  whilst  others 
exert  their  influence  along  the  whole  alimentary  canal. 
5th.  Lastly,  it  is  believed  that  the  study  of  the  phenomena 
connected  with  the  diffusion  of  liquids,  will  have  an  important 
bearing  on  our  knowledge  of  the  real  condition  of  matter,  and  per- 
haps throw  some  light  on  molecular  motion  as  a  source  of  elec- 
tricity, heat,  and  other  imponderable  influences,  thus  rendering 
its  investigation  worth}'  alike  of  the  philosopher  and  the  chem- 
ist. 
PHARMACEUTICAL  GLEANINGS  AND  NOTICES. 
By  the  Editor. 
On  Coating  Pills. — Mr.  Barnard  S.  Proctor,  of  New  Castle 
on  Tyne,  England,  has  published  a  long  list  of  experiments  on 
the  relative  merits  of  processes  for  coating  pills,  which  have 
obtained  in  England,  some  of  which  appear  to  be  highly  ob- 
jectionable. In  the  anxiety  to  render  pills  tasteless,  it  is  but  too 
apparent  that  pharmaceutists  are  tempted  to  overlook  the  effect 
of  the  coating  to  retard  their  action  as  medicines.  The  author 
gives  forty-five  distinct  modifications  of  the  process,  among 
which  the  following  liquids  are  employed  to  moisten  the  pills, 
and  the  following  powders  to  roll  them  in  afterwards  : 
Albumen,  or  white  of  eggs;  water;  simple  syrup;  mucilage 
of  gum  arabic ;  Canada  balsam,  diluted  with  two  parts  of  alco- 
hol ;  melted  white  wax  ;  tincture  of  shellac  ;  collodion  ;  solution 
of  gelatin  ;  alcohol  and  syrup,  equal  parts ;  tincture  of  tolu ; 
tincture  of  sandarach,  and  tincture  of  resin. 
The  powders  employed  are  tragacanth ;  tragacanth  and 
sugar,  equal  parts  ;  powdered  French  chalk  ;  lycopodium;  pow- 
dered sugar;  magnesia;  silver  leaf;  resin  and  French  chalk, 
equal  parts,  and  shellac  and  pumice  stone  powder^  made  by 
rubbing  shellac  and  pumice  with  water  to  a  creamy  consistence, 
and  drying  the  powder.     These  materials  were  employed  in 
