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ON  THE  MANUFACTURE  OF  CITRIC  ACID.  169 
caproYc,  caprylic,  cenanthylic,  and  pelargonic.  This  is  the 
mixture  which  is  to  be  etherized.  Alcohol  is  sometimes  scented 
with  the  product  obtained  by  etherizing  cocinic  acid,  extracted 
from  cocoa-nut  oil ;  to  obtain  this  acid,  saponify  cocoa-nut  oil 
by  potash,  decompose  the  soap  by  hydrochloric  acid,  dissolve 
the  acid  thus  obtained  in  alcohol,  and  pass  into  it  a  current  of 
dry  hydrochloric  acid ;  a  yellowish  liquid  will  be  the  result ; 
wash  it  with  water  and  with  alkaline  water,  when  pure  cocinic 
ether  will  remain,  which  mix  with  ten  times  its  volume  of 
alcohol.  The  richness  of  commercial  essences  in  pure  essen- 
ces may  be  ascertained  by  distillation  ;  alcohol  boils  between 
80°  and  85°,  and  the  essence  remains  as  a  residue.  Artificial  es- 
sences are  not  generally  used  in  perfumery,  excepting  essence 
of  mirbane;  but  other  agreeably-scented  essences  will  very 
probably  be  some  day  used,  carefully  combined  and  consider- 
ably diluted.  As  found  in  commerce,  they  have  an  odor 
which  is  far  from  agreeable,  and  they,  moreover,  have  an  injuri- 
ous effect  on  the  animal  economy  when  inhaled  in  sufficient 
quantity ;  they  must  then,  if  used,  be  used  sparingly. — Ohem. 
News.  Dec.  22,  1865,  Des  Odeurs,  des  Parfums,  et  des  Cosmeti- 
ques. 
ON  THE  MANUFACTURE  OF  CITRIC  ACID. 
By  Feederick  Row,  F.  C.  S. 
As  so  little  attention  has  hitherto  been  given  to  the  manufac- 
ture of  these  organic  acids  by  scientific  men  (probably  on  account 
of  the  small  quantity  annually  produced),  a  few  observations  from 
practical  experience  may  not  I.  e  uninteresting. 
The  first  point  of  importance  in  this  manufacture  is  the  defeca- 
tion of  the  lime  or  lemon-juice  imported,  and  from  which  almost 
all  the  citric  acid  of  commerce  is  produced. 
This  juice  contains,  besides  the  citric  acid,  a  large  quantity  of 
coloring  matter,  mucilage,  and  other  impurities,  which  in  the 
ordinary  method  of  working  so  contaminates  the  citrate  of  lime 
next  produced  as  to  render  the  subsequent  solution,  and  also  the 
crystals  of  citric  acid,  so  impure  that  repeated  re-crystallization 
and  re-saturation  are  necessary  to  render  them  fit  for  the 
market. 
