78  Fat  Decomposition  and  Glycerin.      { Are*braaS  Pi9iom* 
The  product,  based  on  a  total  distillation : 
Distilled  fatty  acid  355,725  lbs.  83.97  per  cent. 
Tar  residue    65,419  lbs.  .        15.44  per  cent. 
Total  recovered  product  421,144  lbs. 
Showing  a  loss  of                               2,548  lbs.  .59  per  cent. 
423,692  lbs.  100.00  per  cent. 
The  yield  based  on  analysis  of  black  oil : 
Distilled    fatty   acid  342,505  lbs.  82.31  per  cent. 
Glycerin                                                5,775  lbs.  1.40  per  cent. 
Tar                                                  65,4,19  lbs.  1572  per  cent. 
413,699  Ids. 
Laboratory   test   -.58.32  per  cent.  410,333  lbs. 
Glycerin  82  per  cent.  5,775  lbs. 
416,108  lbs. 
Equals  a  loss  of  2409  lbs.,  or  .60  per  cent. 
The  yield  based  on  total  product  handled : 
Distilled   fatty   acid  355,7^5  lbs.  49.31  per  cent. 
Glycerin    5,775  lbs.  .82  per  cent. 
Tar   65,419  lbs.  9.70  per  cent. 
Total  recovered  59-20  per  cent,  of  foots 
Laboratory  test  59-55  per  cent. 
Loss   35  per  cent. 
The  manufacturers  of  lard  compounds  refine  their  own  cotton 
oil  and  sometimes  decompose  the  resulting  foots  into  black  oil  for 
economy  in  storage.  This  black  oil  is  marketed  for  Twitchell,  a 
test  of  a  car  showed  :  black  oil,  45460  lbs. ;  reagent,  2025  lbs. 
Product : 
Distilled    fatty   acid                            30,618  lbs.  67.35  per  cent. - 
Glycerin                                              3,173  lbs.  6.98  per  cent. 
Tar                                                    11,028  lbs.  24.25  per  cent. 
Loss                                                    641  lbs.  142- per  cent. 
45,460  lbs. 
100.00  per  cent. 
