372 
Incompatibility  of  Chloral  Hydrate. 
{ 
Am.  Jour.  Pharm. 
Aug.,  1885. 
In  this  experiment  J  it  will  be  noted  that  the  ingredients  differ  from 
the  original  prescription  only  in  the  substitution  of  diluted  alcohol  for 
the  paregoric.  After  standing  a  short  time  this  mixture  separated  into 
two  layers,  the  upper  layer  being  of  a  light  straw  color. 
Exp.  3.  This  experiment  was  with  the  same  ingredients  used  in 
No.  2,  except  that  the  alcohol  was  not  added  until  after  the  mixture 
had  been  standing  for  an  hour.  No  separation  took  place  before  the 
addition  of  the  three  fluidrachms  of  alcohol,  but  the  separation  occurred 
promptly  after  the  addition  of  the  alcohol.  These  experiments  prove 
that  the  alcohol  is  the  cause  of  the  trouble,  and  the  Avriter  thinks  that 
the  chloral  hydrate  is  changed  into  the  less  soluble  chloral  alcoholate. 
In  addition  to  the  experiments  which  have  been  described  numerous 
other  ones  were  tried,  which  served  to  confirm  the  results  of  those 
named.  The  Avriter  found  that  the  addition  of  potassium  bromide, 
sodium  bromide,  sodium  chloride  and  magnesium  sulphate  to  strong 
solutions  of  chloral  hydrate  together  with  the  presence  of  alcohol  deter- 
mined a  separation  of  the  liquids  into  two  layers.  Ammonium  chloride, 
ammonium  bromide,  potassium  nitrate  and  calcium  bromide  did  not 
disturb  the  same  chloral  solutions. 
The  practical  lesson  to  be  learned  from  this  incompatible  prescrip- 
tion, is  that  alcoholic  preparations  should  not  be  prescribed  with  chloral 
hydrate,  especially  not  in  connection  with  the  bromides  of  potassium 
and  sodium,  because  if  the  solutions  used  are  at  all  concentrated  the 
chloral  will  separate  as  alcoholate,  float  on  the  surface,  and  a  great  risk 
will  be  incurred  of  giving  a  large  overdose,  the  patient  having  received 
no  caution  with  regard  to  the  necessity  of  shaking  the  contents  of  the 
bottle  before  taking  a  dose. 
DUNLAP'S  DiAKRHCEA  MIXTURE.— 
R.      Tincture  of  opium  
Tincture  of  camphor  
M.  Dose,  a  teaspoonful  diluted  with  sweetened  water,  after  each  opera- 
tion. This  is  especially  good  in  cholera  moihu^.—New.  Eng.  Med.  Monthly^ 
April,  18S5. 
Tincture  of  peppermint. 
Tincture  of  ginger  
Tincture  of  capsicum  
Hoffman's  anodyne  
.aa   ^  ss 
aa  ss 
