Am.  Jour.  Pharm. 
July,  1898. 
Laboratory  Notes. 
341 
mix  unless  thoroughly  agitated,  and  upon  drawing  it  off  without 
proper  care  in  this  respect  a  variable  lot  of  oil  will  result. 
One  experience,  however,  illustrates  how  necessary  it  is  to  know 
all  the  facts  pertaining  to  the  subject  before  arriving  at  a  conclusion. 
Almost  two  years  ago,  one  of  the  writers  examined  a  lot  of  five 
cans  of  ofl  of  sassafras  which  had  been  received  from  a  distiller  in 
Maryland.  It  was  found  to  be  low  in  specific  gravity  (about  1-055), 
and  was  so  reported. 
The  distiller  wrote  that  it  probably  had  congealed  and  needed 
thawing  out. 
Another  examination  was  made  after  inserting  a  stick  and  thor- 
oughly stirring  the  contents,  to  make  certain  of  the  absence  of  any 
crystals  in  the  bottom.  The  gravity  was  practically  the  same,  and 
the  distiller  was  notified  that  the  oil  had  been  rejected. 
He  arrived  the  next  day,  very  much  excited,  bringing  his  hydro- 
meter along.  Upon  being  shown  the  oil  he  asked  for  a  five-gallon 
bucket,  and,  after  pouring  out  about  two  and  one-half  gallons,  shook 
the  remainder  up  vigorously  in  the  can,  and  we  took  the  specific  grav- 
ity;  it  was  over  ro8,  and,  when  thoroughly  mixed,  the  entire  lot  was 
just  1-07,  as  claimed.  It  was  stated  by  the  distiller  at  the  time,  and 
has  been  verified  by  the  experience  of  the  writers,  that  the  separa- 
tion into  layers  after  the  oil  has  crystallized  and  been  thawed 
out  is  so  marked  that  the  only  way  to  insure  a  homo- 
geneous product  is  to  pour  part  of  it  out  before  agitating,  which 
agitation  must  even  then  be  very  vigorous. 
The  distiller  also  made  the  statements  that  congealation  was  not  ne- 
cessary to  produce  such  a  separation,  and  that  pure  oil  would  always 
separate  into  three  layers  of  different  densities  after  standing  for 
some  length  of  time. 
This  was  somewhat  doubted,  but  the  following  experiment  was 
undertaken  to  decide  the  matter.  A  glass-stoppered  cylinder, 
about  30  inches  high  and  4  inches  in  diameter,  was  filled  with  the 
oil  obtained  from  the  person  making  the  above  statement.  . 
It  was  allowed  to  stand  exactly  one  year  without  being  disturbed, 
and  the  specific  gravities  were  taken  of  samples  siphoned  from  the 
top,  middle  and  bottom,  with  the  following  results  : 
Top,    Sp.  Gr  1-06864  at  150  C. 
Middle,    "         .  :  1-06964  at  150  C. 
Bottom,    "   1-06984  at  1 50  C. 
