^SpimLr!'^™:}         Concentrated  Milk  Products.  657 
ble  conditions,  "should  not  be  used  as  a  permanent  food  when 
good  fresh  cow's  milk  can  be  obtained"  (Holt). 
The  composition  of  human  milk  averages  fat  3.5  percent.,  pro- 
tein 1.5  per  cent.,  and  sugar  7  per  cent.;  cow's  milk  averages  fat 
4  per  cent.,  protein  3.5  per  cent.,  and  sugar  4.50  per  cent.  The 
U.  S.  (Federal)  minimum  standard  for  cow's  milk  is  fat  3 . 5  per  cent., 
non-fatty  solids  8.5  per  cent.  (U.  S.  D.  20th  Edit.,  1918,  1498). 
KVAPORATKD  MIIvKS. 
Evaporated  milk,  formerly  mis-named  evaporated  cream,  is  an 
evaporated  milk  representing  from  two  to  two  and  a  half  times  its 
volume  of  fresh  milk  and  containing  no  cane  sugar.  It  is  an  un- 
sweetened condensed  milk.  It  has  the  consistency  of  thin  cream 
and  is  much  less  sweet  than  condensed  milk.  It  is  sold  in  cans  and 
in  many  large  cities  is  delivered  fresh  daily  in  bulk. 
Commercially,  it  is  made  by  evaporating  fresh  milk  in  vacuo 
until  the  volume  of  liquid  is  from  40  to  50  per  cent,  of  the  original 
volume,  placing  it  in  cans  and  then  sterilizing  the  contents  by  sub- 
jecting the  cans  to  steam  under  pressure.  The  temperature  must 
be  "high  enough  and  maintained  long  enough  to  insure  absolutely 
sterility  to  the  product  and  to  give  the  milk  sufficient  body  to  pre- 
vent the  separation  of  the  butter  fat  in  subsequent  transportation 
and  storage."  ("Milk,"  U.  S.  Department  of  Labor,  Bulletin  Pubh- 
cation  No.  35,  191 8.) 
The  Federal  regulations  require  that  evaporated  milk  must  be 
made  from  whole,  fresh,  clean  cow's  milk  and  must  contain  at  least 
7.8  per  cent,  fat  and  not  less  than  25.5  per  cent,  total  milk  solids 
(Food  Inspection  Decision  No.  158,  U.  S.  Department  of  Agricul- 
ture, April  2,  1 91 5).  It  will  be  noted  that  the  standard  required 
for  milk  solids  in  evaporated  milk  is  nearly  the  same  as  that  for  con- 
densed milk. 
Evaporated  milk  is,  or  should  be,  absolutely  sterile  and  will 
keep  almost  indefinitely  so  long  as  the  can  is  unopened;  once  opened, 
however,  it  rapidly  decomposes  (but  does  not  sour  first,  like  con- 
densed milk,  it  putrefies) ;  it  should  be  kept  well  iced  and  used  in  a 
day  or  two. 
Chemical  Age  (June,  1920,  188)  states  that:  "As  a  matter  of 
more  than  passing  interest  it  should  be  noted  that  evaporated 
milk,  part  or  full  skimmed,  modified  with  foreign  fat  or  vegetable 
oils,  has  been  used  in  increasing  quantities  as  a  substitute  for  true 
