588 
Examination  of  Beeswax. 
fAm.  Jour.  Pharm, 
\  Dec.,lS93. 
amount  of  iodine  absorbed  by  the  wax  being  small  it  was  necessary  to 
use  a  larger  quantity  of  the  substance  than  ordinarily,  consequently 
more  chloroform  was  needed.  The  method1  in  detail  is:  dissolve 
two  grams  of  the  wax  in  40  cc.  of  chloroform  in  a  glass  stoppered 
flask.  Add  25  cc.  of  an  iodine  solution,  containing  25  gms.  of  iodine 
and  30  gms.  of  mercuric  chloride  dissolved  in  95  per  cent,  alcohol 
and  made  up  to  one  liter,  and  shake.  Place  the  flask  into  a  dark 
closet  for  three  hours,  then  add  15  cc.  of  a  10  per  cent,  solution  of 
potassium  iodide  and  100  cc.  of  water,  finally  titrate  the  free  iodine 
with  a  standardized  solution  of  sodium  thiosulphate.  The  "  Iodine 
Number"  expresses  the  per  cent,  of  iodine  absorbed  by  the  wax.  It 
is  quite  essential  to  carry  blank  experiments  in  order  to  secure 
reliable  results. 
The  Melting  Point. — This  is  determined  as  follows :  dip  the  bulb 
of  the  thermometer  into  the  sample  of  melted  wax,  for  an  instant, 
on  cooling,  the  bulb  is  covered  with  a  film  of  the  wax,  introduce 
the  thermometer  into  a  wide-mouthed  bottle  through  its  perforated 
cork.  The  bottle  is  now  hung  into  a  beaker  containing  water  at 
about  65°  C;  carefully  noting  the  temperature  at  the  instant  a  hang- 
ing drop  is  formed,  this  is  taken  as  the  melting  point.  Other2  meth- 
ods were  used  but  the  above  method  gave  concordant  results  with- 
out consuming  too  much  time. 
Specific  Gravity? — This  was  obtained  by  diluting  alcohol  so  that 
the  wax,  previously  melted  and  cooled  normally  would  float  indiffer- 
ently in  it.  The  specific  gravity  of  the  alcohol  being  identical  with 
that  of  the  floating  wax  it  is  necessary  only  to  secure  the  specific 
gravity  of  the  liquid  with  a  picnometer  or  a  specific  gravity  spindle 
and  we  have  the  specific  gravity  of  the  wax.  The  most  trustworthy 
methods  employed  for  securing  the  specific  gravity  of  fats,  waxes* 
etc  ,  are  given  in  the  U.  S.  Bull.,  No.  13,  40-43. 
Stearin,  Stearic  Acid,  etc. — Any  foreign  acid  can  easily  be  detected 
1  U.  S.  Bull.,  Xo.  13,  818. 
2  1S83,  Guichard,  Proc.  Roval  Soc.  Ed.,  106,  432,  532  ;  Zeit.  aual.  Chem... 
2,  70. 
1884,  H.  Kriiss,  Zeit.  f.  Instrumentenkunde,  4,  32. 
1SS6,  C.  Reinhardt,  Zeit.  anal.  Chem.,  25,  n. 
1887,  H.  W.  Wiley,  J.  Anal.  Chem.,  1,  39. 
3  1S79,  Hager,  Analyst,  4,  206. 
