596  Analytical  Researches  and  Investigations  { '^"'iic^'^iss?'^™^ 
ANALYTICAL  RESEARCHES  AND  INVESTIGATIONS. 
Collated  by  Pkof.  Frederick  B.  Power,  Ph.D. 
xi  new  Method  of  Teding  Butter  for  Foreign  Fats.  By  T.  Taylor. — A 
piece  of  pure  batter,  to  which  two  drops  of  sulphuric  acid  are  added, 
gives  a  whitish  yellow,  uutrausparent  liquid,  iu  which,  after  about  five 
minutes,  a  very  pale  scarlet-red  coloration  begins  to  appear  at  the  edges. 
Fresh  oleomargarin  from  beef  tallow  gives  immediately  a  transparent, 
amber-colored  liquid,  which,  after  twenty  minutes,  appears  of  a  deep 
carmine-red  color;  with  old  and  rancid  oleomargarin,  the  liquid 
becomes  dark-brown  and  nntransparent.  Plant  fats,  as,  for  instance, 
cocoanut  oil,  give  a  pale  amber-colored  liquid,  which,  in  about  thirty 
minutes,  assumes  a  pale  red  color,  readily  changing  to  violet.  —  Chem. 
Zeitung,  No.  34,  1882,  from  Bieder mannas  C.-BL,  ii,  345. 
On  the  Detection  of  Artijicicd  Butter.  By  P.  Casamajor. — The  author 
brings  a  specimen  of  the  butter,  previously  melted  and  freed  from  any 
deposit  or  scum,  into  alcohol  of  a  definite  specific  gravity,  and  observes 
whether  the  fat  sinks,  floats  upon  the  surface,  or  remains  suspended  in 
the  liquid.  In  the  latter  case  the  fat  has  the  same  specific  gravity  as 
the  res])ective  alcohol.  Pure  butter  remains  suspended  at  15°C.  (59°F.) 
in  alcohol  of  the  specific  gravity  0*926,  corresponding  to  53*7  per  cent. 
Fat  and  beef  tallow  on  the  contrary  are  borne  by  alcohol  of  the  specific 
gravity  0'915,  corresponding  to  59*2  per  cent.  In  the  examination  of 
a  mixed  butter  it  is  therefore  necessary  to  form  a  liquid,  by  the  addi- 
tion of  a  specifically  heavier  or  lighter  alcohol,  in  which  the  specimen 
just  floats.  From  the  strength  of  the  alcoholic  mixture  a  conclusion 
may  be  drawn  as  to  the  percentage  amount  of  artificial  butter  in  the 
mixed  butter. — Ibid.,  from  Ihid.,  p.  344. 
The  Estimation  of  Neutral  Fat  in  Mixtures  of  Fatty  Acids.  By  M. 
Groger. — O.  Plaasamann  has  directed  attention  to  the  fact  that  when 
an  alcoholic  solution  of  potassium  hydrate  is  added,  drop  by  drop,  to 
an  alcoholic  solution  of  a  mixture  of  free  fatty  acid  and  neutral  fat, 
only  the  former  becomes  saponified,  while  the  latter  remains  unchanged. 
The  author  has  confirmed  in  general  the  correctness  of  this  statement. 
He  dissolved  to  this  purpose  neutral  beef  tallow  in  boiling  alcohol, 
added  a  few  drops  of  an  alcoholic  phcnolphtalein  solution  and  0*1  cubic 
centimeter  of  one-half  normal  alcoholic  jjotassa  solution;  the  solution 
became  immediately  red,  and  the  color  was  retained,  even  at  the  boiling 
temperature,  for  about  five  minutes,  from  which  it  may  be  seen  that 
the  saponification  indeed  proceeds  very  slowly.  The  author,  therefore, 
proceeds  for  the  separation  of  the  fatty  acid  from  the  neutral  fat  in  the 
