430     ON  THE  FUSING  AND  CONaEALING  POINT  OP  FATS. 
of  a  hydrocarbon  and  an  inactive  oxygen-containing  principle ; 
this  latter  consists,  in  100  parts,  of — Carbon,  74*43;  hydrogen, 
6-46  ;  oxygen,  19-11.  It  is  present  in  the  natural  oil  in  so  small 
quantity  that  only  just  sufficient  for  a  good  elementary  organic 
analysis  was  obtained.  The  hydrocarbon  (safren)  contains 
CioHg,  and  consists,  in  100  parts,  of— C,  88-28;  H,  11-77.  Its 
vapor  density  has  been  found  equal  to  4-84.  Safren  boils  at 
about  156®.  The  oil  further  contains  safrol,  C^qR^qO^,  boiling  at 
between  231°  and  233®.  Safrol  is  insoluble  in  water.  Its  spe- 
cific gravity  is  1-1141  at  0° ;  at  — 20®  it  is  not  frozen.  The 
authors  have  studied  the  action  of  bromine,  of  hydriodic  acid,  of 
perchloride  of  phosphorus,  and  nitric  acid  upon  safrol,  but  state 
that  none  of  these  reactions  gave  such  results  as  they  expected. 
With  bromine,  safrol  yields  a  compound  of  the  formula 
CioH5Br502. — Ckem.  JSfews,  Lond.  July  16,  1869,  from  Bulletin 
de  la  Societe  Chimique  de  Paris y  June,  1869. 
ON  THE  FUSING  AND  CONGEALING  POINT  OF  FATS. 
By  Dr.  Th.  Wimmkl. 
The  temperatures  at  which  fats  fuse  and  congeal  are  given 
very  differently  by  different  authors.  This  difference  may  to  a 
certain  extent  be  accounted  for  by  the  natural  variation  of  the 
fats,  but  from  numerous  observations  of  the  author  is  confined 
to  narrow  limits,  and  the  different  results  are  probably  due  to 
the  frequent  mistaking  of  the  fusing  and  congealing  points,  as 
well  as  to  the  methods  employed  for  ascertaining  them. 
The  temperature  at  which  fats  become  transparent,  and  the 
temperature  at  which  they  become  fluid,  has  been  taken  as  their 
fusing  point.  The  author  reviews  several  methods  and  gives  the 
preference  to  that  of  Bonis  (Annales  de  Chim.  et  de  Phys.  xliv, 
152),  which  with  a  few  modifications  he  adopted  for  his  experi- 
ments. 
Cylindrical  thin-walled  glass  tubes  are  selected,  of  one-eighth 
to  one-sixth  inch  in  diameter  and  perfectly  smooth  inside ;  they 
are  within  an  inch  of  one  end  filled  with  the  fused  fat,  and  after 
it  has  congealed,  laid  aside  for  one  or  two  days  to  allow  the  fat 
to  assume  its  natural  hardness.  Lard  which  had  been  kept  after 
congealing  in  cold  water  for  two  hours,  fused  at  33°  C,  but 
