Am.  Jour.  Pharm.  \ 
February,  1908.  J 
Comparative  Composition  of  Milks. 
63 
mediate  period  of  lactation,  at  least,  the  fat  is  nearer  4  per  cent,  than 
3,  the  proteids  nearer  2  per  cent,  than  1,  and  the  sugar  between  6 
per  cent,  and  7,  or  a  ratio  of  4,  175  and  6-50. 
As  to  the  standard  of  percentages  for  cow's  milk,  American  pedia- 
trists  generally  accept  the  following  :   Fat,  4  per  cent.  ;  proteids, 
3  5  per  cent.,  and  sugar,  4-5  per  cent.,  though  for  the  purpose  of 
ready  calculation,  it  is  often  assumed  that  cow's  milk  contains  fat, 
4  per  cent.  ;  proteids,  4  per  cent.,  and  sugar,  4  per  cent. 
PERCENTAGE   COMPOSITION   OF  VARIOUS  MILKS 
(From  Koenig's  Chemie  der  mens.  Nahr.  u.  Genuss.;  by  Leach) 
Goat's  Milk,  200  samples. 
Ewe's  Milk,  32  samples... 
Mare's  Milk,  47  samp.es. 
Minimum 
Maximum 
Mean 
Minimum 
Maximum 
Mean 
Mean 
Ass's  Milk,  5  samples   Mean 
Fat 
3.10 
7.55 
4.78 
2.81 
9.80 
6.86 
1.21 
1.64 
Proteids 
f  A.O 
22^ 
lC  2 
35  I 
r1 
lC  3 
78 
44 
A. 2.01 
C.  3.94 
09 
4.29 
4.42 
7.46 
6.52 
1.99 
20 
(  A.  0.83 
1  C.  3.59 
r  A. 1.77 
1  C.  5.69 
f  A.  1.55 
C.  4.97 
A. 0.75 
C.  1.24 
A.  1.55 
2.22 
I 
(  C.  0 
67 
Sugar 
3.26 
5.77 
4.46 
2.76 
7.95 
4.91 
5.67 
5.99 
Ash 
0.39 
1.06 
0.76 
0.13 
1.72 
0.89 
0.35 
0.51 
A  word  or  two  should  be  said  with  reference  to  the  subject  of  the 
proteids  of  milks.  These  are  almost  wholly  casein  and  albumin. 
The  milks  of  those  animals  whose  digestion  is  principally  gastric, 
contain,  in  their  total  proteids,  a  much  larger  proportion  of  casein 
to  albumin,  than  do  the  milks  of  those  animals  whose  digestion  is 
principally  intestinal.  Thus,  Koenig's  analyses  show  that  in  the 
mean,  of  the  minimum  and  maximum  percentages  of  cow's  milk, 
the  ratio  of  casein  to  albumin  is  about  6  to  1,  in  goat's  milk  3  to  1, 
and  in  sheep's  milk  3  to  1,  while  in  mare's  milk  it  is  1-5  to  1,  and 
