Varieties.  129 
portions — from  50  to  100  parts  of  the  acetate  to  100  parts  of  the 
nitrate—the  most  explosible  mixture  being  100  parts  of  the  fused 
nitrate  to  60  parts  of  the  fused  acetate.  When  the  nitrate  is  in  ex- 
cess, the  combustion  is  only  partial  and  of  short  duration  :  when  the 
acetate  is  in  excess,  the  mixture  burns  slowly  and  similarly  to  a  light 
wood. 
A  mixture  of  nitrate  of  soda  and  acetate  of  potash  was  found  to 
have  the  same  explosive  properties,  but  to  be  more  hygroscopic.  "Mix- 
tures of  nitrate  of  potash  with  the  acetates  of  copper  and  baryta  did 
not  yield  an  explosive  product. — Pharm.  Journ.  and  Trans.  Jan.  11, 
1873. 
bcirutics. 
Croton  Chloral  in  Painful  Affections  of  the  Fifth  Nerve. — It  is  perhaps  sur- 
prising that  a  remedy  whose  action  was  several  months  ago  declared  to  be  of 
so  extraordinary  a  character  should  have  received  so  little  attention  at  the 
hands  of  the  profession,  especially  when  this  new  medicine  promised  to  be  so 
efficient  a  weapon  against  some  of  the  most  painful  diseases  known  to  physi- 
cians. Beyond  one  or  two  pharmacological  notices,  the  substance  seems  to 
have  been  altogether  passed  by. 
The  hydrate  of  croton  chloral  was  made  by  Kramer  and  Pinner,  by  the 
action  of  alkalies  upon  dichlorallyl  and  formic  acid.  Its  physiological  action 
was  investigated  by  O.  Liebreich.  He  found  that  in  animals  it  produced  a 
deep  anaesthesia  of  the  head,  without  any  loss  of  sensibility  of  the  body. 
Death  was  caused  by  a  paralysis  of  the  medulla  oblongata.  In  man,  an  anaes- 
thesia of  the  fifth  nerve  only  was  noticed.  The  sensibility  of  the  trunk,  and  the 
pulse  and  respiration,  remained  unaltered. 
Having  procured  some  of  this  substance,  I  determined  to  make  observations 
upon  such  of  my  patients  at  St.  Bartholomew's  as  appeared  likely  to  be  bene- 
fited by  the  use  of  the  medicine.  I  gave  it  to  about  twenty  persons,  nearly  all 
women.  They  varied  in  age  from  seventeen  to  forty-four.  They  were  all  suf- 
fering pains  in  the  regions  supplied  by  the  fifth  nerve, — that  is  the  upper  and 
lower  jaw,  the  face,  and  the  supra- orbital  region  of  the  forehead.  The  pains 
were  paroxysmal.  In  the  majority  of  the  case3  they  were  increased  at  night. 
Fn  nearly  every  one  of  these  cases  there  were  caries  of  the  teeth.  In  about 
half  there  were  signs  of  anaemia.  The  medicine  was  given  in  doses  of  five,  tea 
and  twenty  grains,  dissolved  in  water.  It  was  given  at  night,  just  before  going 
to  bed.  [n  one  case,  where  the  pains  became  aggravated  at  noon  and  at  bed- 
time, it  was  given  just  before  the  increase  of  pain  was  expected.  In  all  the 
patients,  except  two,  great  relief  from  pain  followed  the  dose  of  croton  chloraL 
Some  of  the  patients  said  that  they  slept  well  after  it ;  others,  that  they  did  not 
