PREPARATION  OF  IODIDE  OF  POTASSIUM.  267 
far  the  use  of  diseased  meat  affects  the  human  constitution  is  un- 
known. In  those  cases  where  certain  parasitic  diseases  exist  in 
animals,  there  is  no  doubt  of  its  injurious  nature;  for  the  tape- 
worm, the  trichina,  and  certain  hydatid  or  encysted  growths  are 
unquestionably  produced  by  it.  Experience  also  points  to  the 
fact  that  carbuncle  and  common  boils  are  in  some  degree  referable 
to  the  use  of  the  flesh  of  animals  affected  with  pleuro-pneumonia ; 
and  occasionally  we  witness  the  most  serious  diarrhoea  and  pros- 
tration of  the  vital  powers  after  eating  diseased  meat.  It  is, 
therefore,  safest  to  forbid  its  use ;  and  it  is  at  all  times  best  to 
guard  against  the  possibility  of  injury  by  having  meat  well 
cooked.  It  should  be  so  cooked  that  the  very  centre  of  the  joint 
should  be  exposed  for  some  time  to  the  temperature  of  212° 
Fahrenheit.  The  instructions  of  Liebig  in  this  particular  are 
hardly  safe  ;  for  although  a  temperature  below  that  of  boiling 
water  may  coagulate  albumen  and  develop  the  flavors  of  cooked 
meat,  it  may  not  ensure  the  destruction  of  dangerous  parasites. 
It  is  therefore  better  to  have  the  meat  a  little  overcooked  than 
otherwise." — Lond.  Pharm.  Journ.,  March  1,  1866,  from  Chem. 
News. 
PREPARATION  OF  IODIDE  OF  POTASSIUM. 
Fuchs  places  100  parts  of  iodine  in  a  porcelain  dish  with 
260  parts  of  distilled  water,  and  adds  thereto  75  parts  of  pure 
carbonate  of  potash  and  30  parts  of  iron  filings.  The  mixture 
is  well  stirred  together,  and  allowed  to  stand.  The  action  pro- 
ceeds slowly  by  itself,  but  is  hastened  by  the  application  of 
heat.  When  the  evolution  of  carbonic  acid  has  ceased,  the 
mixture  is  evaporated  to  dryness  with  continual  stirring. 
It  is  better  to  allow  the  mixture  to  stand  for  some  time  in  a 
lukewarm  drying  oven  until  all  the  iron  is  peroxidized,  and 
then  evaporate  to  dryness.  The  dried  mass  is  then  placed  in 
an  iron  vessel  and  heated  to  a  dull  redness.  The  residue  is 
then  extracted  with  the  smallest  quantity  of  distilled  water  ;  the 
solution,  which  has  usually  an  alkaline  reaction,  is  then  satu- 
rated with  hydriodic  acid,  and  set  aside  to  crystallize. — Chem. 
News,  Dec.  22,  1865,  from  Dingier' \s  Polytech.  Jour.,  Bd.  177,  s. 
251.  ' 
