ItfO      ON  THE  MEDICINAL  PREPARATIONS  OF  GLYCERINE. 
forming  on  cooling  a  transparent  gelatinous  mass.  With  6  parts 
of  glycerin,  the  mass  deposits  a  part  of  the  sulphate  in  warty 
crystals,  which  after  the  whole  being  rubbed  in  a  mortar,  form  a 
kind  of  cerate. 
By  the  aid  of  heat  tannin  may  be  dissolved  in  4  parts  of 
glycerin  ;  the  solution  is  thick  and  cannot  be  filtered  through 
paper. 
One  part  of  muriate  of  morphia  may  be  made  into  a  sort  of 
cerate  with  5  parts  of  glycerin. 
Sugar  is  in  glycerin  soluble  only  to  l-10th  part,  on  account, 
as  it  seems,  of  the  water  contained  in  it. 
5  parts  of  glycerin  and  1  of  gum  arabic  form  a  transparent 
mucilage  ;  1  part  of  glycerin  to  3  parts  of  powdered  gum  arabic 
unite  to  a  thick  mass,  which,  when  spread,  adheres  well  and  is 
very  flexible ;  a  few  drops  of  glycerin  added  to  the  court 
plaster  mass  makes  it  pliant  and  prevents  the  spread  plaster  from 
cracking. 
Glycerin  mixed  with  an  equal  part  of  tar  and  strained,  forms 
a  tar  glycerole  of  a  dark  amber  color,  strong  smell,  and  oily  con- 
sistency, serviceable,  perhaps,  in  certain  diseases  of  the  skin. 
Equal  parts  of  gum  ammoniac  and  glycerin  unite  to  the  con- 
sistency of  plaster,  1  part  of  the  first  to  7  of  the  latter  to  a 
cream-like  glycerole,  which  may  be  strained  through  linen,  and 
after  months  standing  does  not  separate. 
Camphor  is  soluble  only  in  400  parts  of  glycerin,  but  more 
after  it  has  been  rubbed  up  with  alcohol  or  ether. 
Starch  and  glycerin  in  equal  quantities  form  a  sort  of  pomade, 
which  may  be  mixed  with  salts,  alkaloids,  soaps,  extracts,  tar, 
&c.  The  same  results  form  1  part  of  powdered  althaea  to  3  parts 
of  glycerin. 
The  authors  believe  that  fats  extracted  from  fresh  herbs  little 
more  than  chlorophyll,  wax,  aromatics,  and  coloring  matter, 
whilst  glycerin  would  dissolve  gum,  sugar,  tannin,  extractive 
matter,  watery  juices,  alkaloids  and  the  aroma.  It  also  dis- 
solves the  aqueous  and  alcoholic  extracts  in  considerable  quan- 
tity. 1  part  of  it  added  to  fifty  parts  of  collodion  impart  to 
this  preparation  flexibility  and  elasticity. 
The  general  results  of  these  experiments  are  : — 
