150  Manufacture  of  Acetone.  (Affi£(Ssfm" 
was  passed  in  in  4*5  hours.  About  24*5  Gm.  of  acid  came  over  unchanged, 
leaving  159  1  Gin.  decomposed. 
The  acetone  was  estimated  at  537  Gm.,  or  about  34  p.  c.  of  the  decomposed 
acid. 
(8)  Charged  the  rotary  still  with  1,000  Gm.  of  dry  barium  acetate  and  distilled 
this  acetate  as  long  as  it  would  yield  a  distillate,  and  until  it  was  reduced  to 
about  770  Gm.  of  barium  carbonate  quite  free  from  acetate.  This  yielded  ace- 
tone estimated  by  iodoform  at  about  60  p.  c.  of  the  theoretical  quantity. 
When  the  distillation  from  the  acetate  had  ceased  the  receivers  were  changed 
and  490  Cc.  of  60  p.  c.  acid  =  294  Gm.  of  absolute  acid  were  passed  into  this 
charge  of  carbonate  in  about  4*5  hours. 
The  distillate  was  received  in  5  fractions. 
1st.    37  Cc.  of  acid  water  containing  15*6  p.  c.  acid  or  577  Gm. 
2d.  256   "    "  dilute  acetone    "  4-4     "     "  "  11-26  " 
3d.  230   "   "     "         "        "  9.6     "  "  22-08  " 
4th.   46   "   "     "         "  no     "     "  "   5-06  " 
5th.   26   "   "     "         "        "  17-6     "     "  "   4-58  " 
595  Cc.  Distilled  over  undecomposed,  4875  Gm. 
294  Gm.  — 49  Gm.  =  245  Gm.  decomposed. 
In  each  of  the  2d  and  3d  flasks  was  about  40  Cc.  of  water  at  the  start.  Then 
80  from  595  gave  515  Cc.  of  total  distillate  from  the  490  Cc.  fed  in. 
Acetone  required  from  245  Gm.  acid  118  Gm.  Estimated  yield  71  Gm.,  or  60 
p.  c.  of  the  required  yield. 
On  the  following  day,  without  having  opened  the  still,  it  was  reheated  and 
530  Cc.  of  60  p.  c.  acid  =318  Gm.  of  absolute  acid  was  passed  in  in  vapor. 
From  low  street  pressure  in  the  gas  mains  the  heat  on  this  day  was  deficient. 
1st  distillate   50  Cc.  acid  water  containing  19*6  p.  c.  acid  or  9  8  Gm. 
2d       "        255   "    dilute  acetone     "        io*o    "      "     "  25*5  ' " 
3d       "        138  "       "         "         «         6-o    "      "     "  8-2  " 
443  Cc.  43-6  Gm. 
318  Gm.  —  44  Gm.  =  274  Gm.  acid  decomposed. 
Acetone  required  from  274  Gm.  acid  132  Gm.  Estimated  yield  95  Gm.  or 
72  p.  c.  of  the  required  yield. 
On  the  day  following,  again  without  opening  the  still,  in  about  4  hours, 
passed  in  535  Cc.  of  60  p.  c.  acid  =  321  Gm.  of  absolute  acid, 
1st  distillate,  hot  flask,   22  Cc.  acid  water  containing  7*6  p.  c.  acid  or  1*67  Gm. 
2d        "       ice-bath,  258  "  dilute  acetone    "        4.8     "      "    "  12-38  " 
3d        "  "        131  "       "        "         "        7-6    "      "    "   9-96  " 
411  Cc.  24-01  Gm. 
231  Gm.  —  24  Gm.  =  297  Gm.  acid  decomposed. 
Acetone  required  by  theory  from  297  Gm.  acid  143  Gm.  Obtained  by  esti- 
mate about  113  Gm.  or  nearly  80  p.  c.  of  the  required  yield. 
