68 
Emulsion  of  Terebene. 
/  Am.  Jour.  Pharm. 
I        Feb.,  1888. 
in  other  words,  the  loss  of  weight  is  equal  to  the  specific  gravity  ; 
from  which  we  deduce  the  following  general  rule  : — 
The  specific  gravity  of  a  liquid  is  equal  to  the  loss  of  weight  (  in 
grains)  sustained  by  a  solid  body  when  immersed  in  the  liquid,  the 
weight  of  the  solid  being  equal  (in  grains)  to  its  specific  gravity. 
Hence  it  is  necessary  only  to  weigh  the  solid  in  the  liquid,  and  its 
loss  gives  at  once  the  specific  gravity  of  the  liquid. 
Taking  the  preceding  example  : — if  200  grains  of  citric  acid  lose  115 
grains,  1*6  grain  will  lose  .920  grain,  and  this  loss  is  equal  to  the 
specific  gravity  of  the  oil. 
In  practice  the  weight  of  the  solid  might  be  10  or  100  times  the 
weight  of  its  specific  gravity,  care  being  taken  to  put  the  decimal 
point  in  the  right  place  in  the  final  result. 
As  perhaps  one  of  the  most  desirable  solid  bodies  to  use,  I  would 
suggest  a  piece  of  aluminium  weighing  256  grains  ;  the  specific  gravity 
of  that  metal  being  2*56.  If  upon  trial  its  specific  gravity 
should  vary  from  these  figures,  its  weight  should  be  made  to  cor- 
respond. 
For  liquids  having  greater  specific  gravity  than  2*56,  it  would  be 
necessary  to  use  a  heavier  solid  than  aluminium. 
EMULSION  OF  TEEEBENE. 
By  Joseph  W.  England,  Ph.G. 
Read  at  the  Pharmaceutical  Meeting,  January  17. 
In  the  internal  administration  of  oleaginous  and  non-oleaginous 
volatile  liquids,  the  tendency  of  the  times  seems  strongly  tending 
towards  the  universal  adoption  of  the  emulsion,  as  the  most  satisfac- 
tory form  of  preparation,  and,  when  it  is  remembered,  especially  as 
regards  the  fixed  and  volatile  oils,  that  the  more  finely  divided  in 
physical  condition,  with  which  they  are  presented  to  the  digestive  ap- 
paratus, the  less  liability  there  is  to  cause  nausea  and  eructation,  and 
the  more  readily  do  they  undergo  digestion  and  absorption  (or  converse- 
ly) the  naturalness  of  using  an  emulsion  is  readily  explained. 
As  a  rule  the  fixed  oils  yield  most  readily  to  emulsionizing  influ- 
ences, so  that  their  suspension  presents  no  especial  difficulties,  but  in 
the  case  of  volatile  oils  and  liquids  we  find  a  different  state  of  affairs. 
Whilst  a  few  of  these  readily  give  good  emulsions,  this  result  is  by 
no  means  a  universal  one,  and  is  secured  only  after  using  relatively 
