AVr°™mt™' }         Rectification  of  Alcohol,  etc.  185 
Fifteen  gallons  of  alcohol,  sp.  gr.  -82361  at  60°  F.  ==  93  per  cent, 
was  poured  upon  seventy  pounds  of  well-burned  lime,  (previously 
broken  into  small  pieces),  in  a  still,  heated  by  a  steam  jacket.  The 
still  was  then  made  tight,  and  heated  to  about  120°  ;  after  standing 
three  days,  a  worm  was  attached  and  distillation  commenced,  protect- 
ing the  distillate  from  the  air.  Bach  gallon  was  collected  in  a  sepa- 
rate vessel,  the  heat  being  gradually  increased  as  was  necessary  to 
cause  the  alcohol  to  pass  over  slowly. 
Ten  gallons  was  all  that  could  be  made  to  pass  over  by  steam  heat. 
Water  was  then  added  to  the  lime  in  the  still,  and  most  of  the  alco- 
hol recovered  as  dilute  alcohol. 
The  ten  gallons  of  strong  alcohol  thus  obtained  was  returned  to  a 
still  with  twenty-five  pounds  of  quick  lime,  and  the  operation  as  above 
repeated.  Eight  gallons  of  alcohol  was  obtained,  separated  as  before 
in  fractional  portions  of  one  gallon. 
The  specific  gravity  of  the  several  portions  taken  on  a  balance  with 
the  one  thousand  grain  bottle,  temperature  at  60°  F.  is  shown  in  the 
following  summary  : 
Gallon. 
First  Distillation. 
Second  Distillation. 
1st. 
•80170 
•80978 
2nd. 
•79756 
•79700 
3rd. 
•79610 
•79461 
4th. 
•79762 . 
•79516 
5th. 
•80040 
•79458 
6th. 
•79593 
•79410 
7th. 
•79782 
•79425 
8th. 
•79632 
•79615 
9th. 
•79706 
10th. 
•79780 
Mean 
•79783 
•79695 
The  density  of  absolute  alcohol  varies  somewhat  with  different  au- 
thorities ;  Drinkwater  and  Fowne  give  '79381,  Tralles,  -7939,  and 
Gay-Lussac,  -7947;  taking  the  mean  of  these  authorities,  we  have 
•79413. 
It  will  be  seen,  on  reference  to  the  figures  given  above,  that  the 
sixth  gallon  of  the  second  distillation  alone  is  absolute,  according  to 
this  mean  standard,  and  that  the  mean  of  the  3rd,  4th,  5th,  6th,  and 
7th  gallon  of  the  second  distillation  is  -79425,  being  within  the  figures- 
given  by  Gay-Lussac. 
