ON  GLYCERIN. 
able ;  in  the  preparation  of  lactucarium  in  a  liquid  form,  by 
which  its  activity  and  reliability  are  more  certain  ;  as  glycerole 
of  aloes,  tar  and  arnica  for  external  use.  It  is  used  with  starch 
in  the  proportion  of  1  oz.  of  glycerin  to  70  grs.  of  starch  for 
making  an  article  called  "  plasma,"  as  a  substitute  for  lard  or 
cerate.  And  it  no  doubt  possesses  advantage  iu  preparing  vege- 
table extracts,  such  as  belladonna,  aconite  and  others  for  exter- 
nal use,  as  they  can  be  readily  mixed  with  it ;  for  liniments,  in 
the  place,  of  oil,  as  it  will  not  become  rancid ;  and  has  been 
suggested  for  the  extraction  of  the  active  principles  of  vegetable 
substances  in  place  of  oil  and  fats,  to  be  used  in  the  preparation 
of  cerates  or  ointments. 
Incorporated  with  vegetable  extracts,  it  will  prevent  mouidi- 
ness  and  keep  them  soft,  and  for  pill  masses  liable  to  become 
hard  it  is  a  good  addition.  It  may  be  used  as  an  addition  to 
poultices  to  keep  them  soft,  or  any  article  to  be  kept  in  a  moist 
or  plastic  condition. 
Its  solvent  and  preservative  properties  are  of  great  import- 
ance to  the  pharmaceutist.  In  the  preparation  of  fluid  extracts,  it 
will  be  found  to  supply  the  place  of  alcohol  and  sugar  to  much 
advantage.  My  experience  is  such  as  to  convince  me  that  in 
most  cases  extracts  will  be  more  permanent  by  supplying  the 
place  of  alcohol  used  to  preserve  them  with  glycerin,.  To  fluid 
extract  of  Jalap,  Veratrum  viride,  Cinchona  aromat.  and  Iris 
versicolor,  glycerin  was  added  and  all  the  alcohol  evaporated  out, 
specimens  of  which  I  now  exhibit,  presenting  a  handsome  ap- 
pearance. Sarsaparilla  and  those  liable  to  fermentation  will  be 
much  better  preserved  with  it. 
I  have  used  glycerin  as  a  menstruum  in  the  preparation  of 
extracts  of  cloves,  nutmegs  and  Ceylon  cinnamon,  and  the 
preparations  are  elegant  representatives  of  the  substances  from 
which  they  were  made. 
It  dissolves  the  vegetable  acids,  most  of  the  vegetable  alka- 
loids, sulphuret  of  potassium,  permanganate  of  potassa,  sulphate 
of  copper,  zinc,  iron  and  potassa,  alkaline  and  some  of  the  me- 
tallic chlorides ; 
Iodide  of  ammonium,  cadmium,  ainc,  potassa,  aadiam,  lime 
and  manganese ; 
