Am.  Jour.  Pharm.  \ 
February,  1897.  J 
Terpin  Hydrate. 
75 
(1)  Oil  of  turpentine  
(2)  Methyl  alcohol  (sp.  gr.,  o'8oi) 
(3)  Nitric  acid  (sp.  gr.,  1*35)  .  .  . 
120  c.c. 
30 
30 
These  liquids  were  mixed  in  the  order  indicated  and  allowed  to 
stand  in  a  flask  three  days  and  then  poured  into  a  flat  dish.  Taking 
advantage  of  the  very  slight  solubility  of  terpin  hydrate  in  water, 
30  c.c.  of  this  liquid  were  added  to  the  mixture,  with  the  result  that 
the  crystals  separated  in  a  much  shorter  time  than  they  did  with 
the  methods  previously  employed.  No  additional  crystals  were 
formed  on  allowing  the  mixture  to  stand  several  days.  The  weight 
of  the  crystals  obtained  was  7-32  grammes,  and  these,  on  purifying 
from  hot  solution  of  methyl  alcohol,  yielded  3  2  grammes  of  terpin 
hydrate,  which  answered  to  all  the  tests  for  the  U.S.P.  compound. 
By  further  evaporation  an  additional  quantity  of  crystals  may 
be  obtained. 
The  crystals  obtained  by  the  use  of  methyl  alcohol  had  a  closer 
resemblance  to  the  article  which  is  found  in  the  market,  and  also  a 
more  aromatic  odor  than  those  obtained  by  the  employment  of 
ethyl  alcohol. 
Amyl  alcohol  likewise  may  be  used  in  making  terpin  hydrate. 
An  explosion  occurred  a  few  years  ago  (Proc.  Am.  Pharm.  Assoc., 
1887)  in  a  Parisian  laboratory  during  the  manufacture  of  terpin 
hydrate.    The  following  proportions  of  liquids  were  employed  : 
Oil  of  turpentine  72  Iy. 
Alcohol  50  " 
Nitric  acid   17  Kg. 
The  mixture  was  usually  cooled  in  stone  jars  set  in  water,  but  as 
these  were  all  in  use  at  the  time,  a  part  of  the  mixture  was  poured 
into  a  wooden  cask,  to  cool  off,  and  as  the  wood  did  not  conduct 
the  heat  away  rapidly  enough,  a  violent  explosion  took  place,  doing 
much  damage. 
Indian  podophyllum,  according  to  W.  R.  Dunstan  {Imp.  Inst.  Jour.,  Decem- 
ber, 1896),  is  derived  from  Podophyllum  emodi,  and  contains  two  to  three 
times  as  much  resin  as  the  American  podophyllum  from  P.  peltatum.  Dr. 
Mackenzie  finds  that  the  two  resins  (Indian  and  American)  are  identical  in 
their  medicinal  effects,  and  that  there  is  no  reason  why  the  resin  obtained 
from  the  Indian  drug  should  not  be  substituted  for  the  American  resin. 
