PREPARATION  OF  CHLOROFORM,  ETC. 
25 
atic  acid,  I  added  an  additional  quantity  of  acid  and  continued 
the  digestion  several  hours  more. 
A  large  amount  apparently  remained  undissolved  ;  allowing 
this  to  settle,  and  pouring  off  the  clear  solution,  I  threw  the 
bulky  sediment  on  a  filter  and  washed  with  water  thoroughly. 
When  dried,  it  resembled  white  clay,  and  weighed  1\  oz.,  which 
represents  this  moderate  adulteration  as  42  per  cent,  of  the 
whole  weight.  But  this  was  not  all :  upon  evaporating  the  acid 
solution,  together  with  the  wash  waters  of  the  sediment,  it  be- 
came encrusted  over  with  a  crystalline  mass  ;  pouring  off  the  now 
concentrated  solution,  and  washing  the  crystals  with  cold  water 
and  drying,  I  obtained  a  further  adulteration  of  80  grains,  or 
nearly  6  per  cent,  of  fine  silky  crystals,  white,  and  resembling 
sulphate  of  quinine.  Subjecting  these  impurities  to  appropriate 
tests,  it  is  evident  that  the  first  mentioned  insoluble  residue  is 
alumina,  while  the  crystals  are  hyd rated  sulphate  of  lime  de- 
posited from  the  hot  solution. 
Can  you  inform  us,  Mr.  Editor,  by  what  ingenious  process 
this  lot  of  Prec.  Carb.  of  Iron  has  been  manufactured  ?  for  I 
imagine  the  whole  compound  has  been  thrown  down  together  by 
some  unscrupulous  chemist,  who  was  more  concerned  about  the 
quantity  than  the  quality  of  the  article. 
Yours,  truly, 
W.  H.  Pile. 
NOTE  ON  THE  PREPARATION  OF  CHLOROFORM,  AND  OF  OIL  OF 
CLOVES. 
By  the  Editor. 
Recently  at  the  invitation  of  Mr.  Benjamin  J.  Crew,  of  the 
firm  of  Crew,  Rogers  &  Crew,  manufacturing  chemists  of  this 
city,  the  Editor  of  this  Journal  had  the  opportunity  of  examin- 
ing the  apparatus  employed  by  these  gentlemen  in  the  manufac- 
ture of  chloroform  and  oil  of  cloves.  The  chloroform  still  is 
peculiarly  located,  being  sunk  in  the  ground;  the  top  of  the  still 
is  on  a  level  with  the  first  floor  of  the  laboratory  building,  whilst 
the  body  of  the  still  occupies  a  circular  pit,  walled  with  brick, 
furnished  with  a  lateral  opening  into  the  coiitfnon  sewer,  into 
which  the  calcareous  residue  of  the  process  is  allowed  to  escape. 
