336 
Tincture  of  Kino. 
Am.  Jour.  Pharm. 
July,  1880. 
become  loosened  through  the  contraction  induced  by  the  alcohol  vapor 
as  well  as  by  changing  temperature.  In  all  such  bottles  the  effect  of 
air  on  the  tincture  became  very  manifest.  In  such  that  admitted 
much  air  gelatinization  became  complete.  If,  however,  the  precaution 
is  taken  to  look  after  the  corks  and  keep  them  fastened  no  deteriora- 
tion results.  When  a  vial  was  partially  emptied  the  remainder  in- 
variably jellied  in  due  time.  The  addition  of  glycerin  before  or  after 
gelatinizing  had  no  visible  effect,  either  in  preventing  the  alteration 
or  regenerating  the  spoiled  tincture.  As  some  loss  and  inconvenience 
nevertheless  results  from  this  treatment,  the  writer  concluded  to  test 
catechu  in  this  connection,  as  tincture  of  catechu  never  gelatinizes. 
An  ample  proportion  of  catechu  was  employed,  which,  in  all  proba- 
bility, is  far  in  excess  of  actual  need.  The  success  of  this  process  is 
complete,  as  no  change  occurs  in  tincture  of  kino  so  prepared,  after 
keeping  it  for  upwards  of  eight  months  exposed  to  the  air  with  im- 
punity. That  the  catechu  is  really  protective,  and  not  merely  so  by 
appearance,  for  reason  of  using  an  unchangeable  kino,  is  shown  by 
the  fact  that  the  same  kino,  used  alone,  gives  an  impermanent  tinc- 
ture. Another  remarkable  circumstance  is  that  a  tincture  of  kino, 
already  quite  syrupy  from  oxidation,  when  treated  with  one-third  its 
volume  of  the  catechu-kino  tincture,  ceases  to  thicken  and  remains 
intact  on  unlimited  exposure  thereafter.  It  is  evident  that  the  cate- 
chu is  not  the  preserving  agent,  as  a  tincture  made  by  using  an 
aqueous  extraction  of  the  catechu  is  equally  effective.  The  writer 
recommends  the  following  process  for  preparing  a  permanent  tincture 
of  kino : 
Kino  One  and  a  half  troy  ounces. 
Catechu  Half  a  troy  ounce. 
Alcohol  Four  fluid  ounces. 
Water  safRcient  to  make  one  pint. 
Powder  the  kino  and  catechu,  mix  them,  add  ten  fluid  ounces  of 
water,  heat  for  ten  or  fifteen  minutes  with  constant  stirring,  and  let 
the  mixture  cool.  Now  add  water  to  the  measure  of  twelve  fluid 
ounces  and  then  add  the  alcohol.  Pour  the  mixture  into  a  bottle 
containing  sixty  grains  of  filter  paper,  shake  the  whole  well  at 
intervals  and  strain  the  tincture  through  fabric  after  twenty-four 
hours. 
