COLLODION. 
147 
the  writer's  practice  the  cantharidal  collodion  has  for  some  years 
past  been  increased,  in  the  proportion  of  cantharides  used,  by 
ten  per  cent.,  but  it  is  doubted  whether  this  be  a  sufficient  in- 
crease. It  should  always  be  made  flexible  or  non-contractile, 
and  therefore  requires  more  gun-cotton.  Specimens  of  both 
proportions  are  presented  herewith. 
The  addition  of  a  proportion  of  phenols,  or  carbolic  acid,  to 
the  flexible  collodion  proposed,  will  often  be  found  very  useful 
and  important.  From  one  to  ten  per  cent,  of  the  coal  tar  crea- 
sote,  or  impure  carbolic  acid,  may  be  conveniently  added,  and 
this  mixture  yields  a  film  well  calculated  to  replace  many  of  the 
more  complex  and  clumsy  "  carbolic  acid  plasters  "  in  use. 
^ 
List  of  Samples  of  Collodion. 
\  Number. 
Percentage  of  Gun- 
Cotton. 
1  Percentage   of  Gly- 
1  cerin. 
1  Percentage  of  Castor 
1  Oil. 
Percentage  of  Canada 
Balsam. 
Percentage  of 
,  Cantharides. 
Percentage  of  impure 
1          Carb.  Acid. 
Kemarks. 
1 
3-50 
IStrictly  officinal. 
2 
3-99 
10  p.  c.  increase. 
3 
4-4 
2-48 
Clear. 
4 
4-4 
3- 
Slightly  cloudy. 
5 
4-4 
3-7 
Cloudy. 
6 
4-4 
4-4 
Slightly  milky. 
7 
4-4 
4-62 
Milky. 
8 
4-93 
4-93 
Milky. 
9 
3- 
Prussian  Pharmacopoeia. 
10 
2-6 
British  Pharmacopoeia. 
11 
2-6 
2-65 
5-45 
British  Flexile. 
12 
7-00 
7-00 
Paris  Codex. 
13 
5- 
5- 
Best  flexible  film. 
14 
4-4 
4-4 
15 
7-53 
7-53 
Milky  and  dense. 
16 
7-53 
5- 
Slightly  milky. 
17 
7-53 
3-76 
Clear. 
18 
1-9 
]/2  grain  to  a  minim. 
Strictly  officinal. 
19 
3- 
G-10  grain  to  a  minim. 
10  p.  c.  Canth.  more. 
20 
5- 
5- 
1 
Phenaten. 
21 
5- 
5- 
2 
It  is  suggested  that  all  these  specimens  be  referred  to  the 
Committee  on  Specimens  for  report. 
Brooklyn,  Sept.  2d,  1869. 
— Proc.  Amer.  Pharm.  Assoc.,  1869. 
