A\i°rUi;miRM }        Glycerin  in  Astringents,  etc.  127 
call  attention,  but  to  an  effect  depending  on  another  cause.  Physi- 
cians who  have  been  in  the  habit  of  using  astringents — as  tannic  acid, 
and  some  of  the  preparations  of  iron — have  noticed  that  when  these 
substances*are  mixed  with  glycerin,  a  different,  and  much  milder  effect 
is  realized  than  when  an  aqueous  solution  is  employed.  During  the 
last  few  months,  some  of  the  pharmaceutical  journals  have  alluded  to 
this  effect  ;*  and,  at  the  last  meeting  of  the  British  Pharmaceutical 
Conference,  it  was  made  the  subject  of  a  short  discussion. f  it  was 
then  stated  by  the  president,  that  he  was  aware  of  an  instance  in 
which  three  hundred  grains  of  perchloride  of  iron,  dissolved  in  glyc- 
erin, was  swallowed,  by  mistake,  without  any  ill  effects.  It  is  certain 
that  a  much  smaller  quantity,  in  aqueous  solution,  would  have  pro- 
duced serious  results.  The  common  experience  of  physicians  with 
regard  to  the  comparative  inefficiency  of  glycerinurn  aciditannici  was 
also  alluded  to.  Again,  at  a  meeting  of  the  Pharmaceutical  Society 
held  Dec.  3rd,J  it  was  stated  as  a  well-known  fact,  that,  if  a  greatly 
astringent  effect  is  desired,  the  solution  of  tannin  in  glycerin  must  be 
diluted  with  water ;  and  that  the  same  is  true  in  regard  to  the  styptic 
action  of  a  solution  of  perchloride  of  iron  in  glycerin.  It  was  also 
stated  that  glyeerinum  acidi  carbolici  was  much  milder  in  action  than 
an  aqueous  solution  of  similar  strength.  At  the  last  meeting  of  the 
American  Pharmaceutical  Association  the  effect  of  glycerin  on  astrin- 
gents was  alluded  to  as  having  been  noticed ;  as  all  these  statements 
coincide  with  the  opinions  of  observant  physicians,  this  modifying  ac- 
tion of  glycerin  may  be  recognized  as  an  acknowledged  fact. 
It  becomes  interesting  for  us  to  ascertain  the  cause  of  this  modify- 
ing action ;  and,  in  this  endeavor,  we  may  consider,  first,  the  nature 
of  the  physiological  and  therapeutical  effects  produced  by  astringents  ; 
and,  secondly,  the  effect  of  glycerin  on  the  chemical  properties  of  this 
class  of  remedies. 
In  regard  to  the  first  point  we  find  the  action  of  astringents  is,  in 
great  part,  if  not  entirely,  to  be  attributed  to  their  chemical  agency. 
In  most  instances,  these  bodies  have  an  affinity  for  certain  constituents 
of  the  animal  solids  and  fluids,  and  effect  changes  by  direct  combina- 
tion.   Pharmacologists  are  generally  agreed  on  this  matter,  and  it  is 
*  Glycerin  ;  by  A.  H.  Mason,  F.  0.  S.,  Chemist  $  Druggist,  April,  1873,  p. 
119  ;  and  Can.  Pharm.  Joum.,  No.  lxii,  p.  396. 
t  Pharm.  Jour.  &  Trans.,  Oct.  1873;  and  Can.  Pharm.  Jour.,  Vol.  vii,  p.  172. 
j  Pharm.  Joum.  &  Trans.,  Dec.  1873,  p.  451. 
