Am.  Jour  Pharm.  ) 
Oct.  1, 1874,  J 
The  Chemistry  of  Milk. 
ill 
France  the  licorice  water  is  drunk  at  the  public  rendezvous  under 
the  name  of  "  Coco  ;"  it  is  slightly  laxative  and  cooling,  anti-scor- 
butic, and,  unlike  other  sweets,  it  quenches  thirst.  —  Chemist  and 
Druggist,  August  15,  1874. 
THE  CHEMISTRY  OF  MILK. 
By  Edward  J.  Hallock,  A.  M. 
Like  most  other  articles  of  food,  milk  consists  largely  of  water,, 
nearly  88  per  cent,  being  present  in  pure  and  unadulterated  country 
milk.  Prof.  Wanklyn  gives  the  following  as  the  average  composition 
of  country  milk : 
Water,    .......  87-56  per  cent. 
Fat,  .......  3  07  per  cent. 
Casein,  .......  4-04  per  cent. 
Milk  sugar,  ......  4-62  per  cent. 
Ash,       .......  -71  per  cent. 
100-00 
The  fat,  which  exists  in  the  form  of  minute  globules,  is  a  mixture 
of  olein,  palmitin,  stearin,  butyrin  and  other  fats.  When  the  little 
sacs  containing  this  fat  are  broken  by  agitation,  as  in  the  operation  of 
churning,  the  fats  agglomerate  together  to  form  butter.  The  specific 
gravity  of  milk  fat  is  about  0*9,  while  the  solution  in  which  it  is  sus- 
pended will  average  about  1*03,  so  that  when  milk  is  left  at  rest  for 
two  or  three  hours  it  rises  to  the  top  and  forms  what  is  known  as 
cream.  In  the  manufacture  of  butter,  this  alone  is  employed,  as  it 
contains  all  the  fat,  along  with  the  peculiar  flavoring  matter  of  the 
butter.  According  to  Chevreul,  ordinary  butter  from  cows'  milk  is- 
composed  of  stearin,  margarin  and  olein,  with  small  quantities  of 
butyrin,  caproin  and  caprin,  to  which  its  odor  is  due.  In  fresh  but 
ter,  the  butyric  acid  (C4H802)  is  combined  with  glycerin  to  form 
butyrin,  an  inodorous  substance.  On  standing,  the  butyric  acid  is 
set  free  and  imparts  to  rancid  butter  its  well-known  and  unpleasant 
odor.  Butyric  acid,  although  not  very  pure,  can  be  obtained  by 
saponifying  butter  with  an  alkali  and  distilling  the  soap  with  sulphu- 
ric acid.  It  is  employed  in  the  manufacture  of  butyric  ether,  or  oil 
of  pineapple.  Good  milk  usually  contains  about  10  per  cent,  of 
cream,  and  some  idea  of  the  purity  and  richness  of  the  milk  may  be 
gained  by  pouring  some  of  it  into  a  graduated  glass  tube,  and  notic- 
