As  soon  as  the  butter  has  formed,  it  is  removed  from  the  churn,  and
well  washed  in  water,  it  being  kneaded  at  the  same  time  until  as  much
as  possible  of  the  adherent  and  incorporated  whey  is  removed ;  this  is
known  by  the  water  ceasing  to  become  turbid  and  milky.  If  intended
for  salt  butter,  the  salt  should  be  added  as  soon  as  possible  after
churning  and  washing,  as,  left  for  any  length  of  tin)e,  the  butter  is  apt
to  become  rancid.  Great  attention  should  be  paid  to  the  quality  of
the  salt  used ;  the  best  descriptions  are  rock  salt,  and  that  prepared
from  salt  springs.  Sea  salt,  generally,  is  not  so  good,  on  account  of
the  presence  of  sulphate  of  magnesia,  wiiich  renders  it  somewhat  bitter,
as  well  as  of  chloride  of  calcium,  which  has  a  strong  affinity  for  water,
even  attracting  it  from  tiie  atmosphere.
It  would  be  out  of  place  in  this  report  to  enter  into  the  practical
minutiaj  of  butter-making,  such  as  the  temperature  at  which  the  cream
or  milk  should  be  churned,  the  best  kinds  of  churn,  the  methods  of
churning,  &c.,  all  points  of  the  greatest  importance.
According  to  Chevreul  and  Messrs.  Bromeis  and  Heintz,  butter  con-
tains margaric,  butyroleic,  butyric,  capronic,  caprylic,  and  capric  acids,
together  with  glycerine.  The  margarine  or  margarate  of  glycerine  of
butter  is  solid  ^t  common  temperatures  ;  but  the  combinations  of  its
other  fatty  acids  with  glycerine,  constituting  butyroleine,  butyrine,
capronine,  capryline,  and  caprinine,  are  fluid.
According  to  Bromeis,  100  parts  of  butter  contain  about  G8  parts
of  margarine,  and  30  of  butyroleine  ;  the  remainder  consists  of  the
glycerine  compounds  of  the  other  acids.
